So the Mercs finally broke – and emerging from the desperate dog fight to pick up the pieces was the remarkable Daniel Ricciardo; the first time in his short Red Bull career in which it was possible to take a win and he did so.

Behind him was late carnage as Sergio Pérez and Felipe Massa collided at scarily high speed while fighting for the final podium place. But there was a drive yet more remarkable than Ricciardo’s – that of Nico Rosberg, second in a Mercedes that was minus 160bhp for the last 33 laps and only passed by Danny two laps from the end. A crucial difference in brake balance settings allowed him to pick up a valuable 18 points whilst team-mate Lewis Hamilton was forced to retire, out of brakes.

The braking issues

Montreal’s combination of long straights and slow corners was for many years the toughest test of brakes on the calendar. But such has been the amazing rate of progress in disc materials and caliper technology that for the last few years that aspect of this old-school track had been tamed.

The introduction of the 2014 hybrid cars, though, returned that concern very much back to the forefront of engineers’ concerns. With so much braking now being done by the torque reversal upon the rear axle of the ersK, the brake discs have been reduced in size – mainly for aerodynamic benefit.

Typically the diameter has been reduced by around a centimetre and the thickness is usually around 3mm less than the maximum allowable 28mm. Six-pot calipers have been replaced by four-pots at Mercedes, Red Bull, McLaren and Sauber. Apparently it would even be possible to run no rear brake discs at all if the regulations allowed it; the rear braking could all be done by the ersK. That’s all fine until the ersK fails.

The ersK on both Mercedes ceased to function, as a result of a control electronics unit failure – that of Lewis Hamilton at turn 10 on lap 36, Rosberg’s about 30-seconds later at turn one on lap 37: engines minus 160bhp and severe under-braking on the rear.

Those failures were two of several key factors. Another one was Ricciardo’s stunning in-lap on lap 37, coupled with the rather ordinary out-lap of Sebastian Vettel at the same time, which ensured Danny passed his team-mate. Red Bull had brought Seb in when it did – and not later, as Seb wished – to undercut him past Nico Hulkenberg’s Force India. It was as surprised as Vettel that Ricciardo was able to pass after pitting a lap later.

Possibly even more significant was the wheel gun failure at Williams as Felipe Massa made his first pit stop on lap 15. The left-front gun simply didn’t work and had to be changed. Without the 4s delay that entailed, Massa would not have been behind either the Red Bulls or Pérez’s Force India.

The Massa/Pérez accident

Pérez himself might have used the fantastically easy way he has with marginal option tyres to have kept the Red Bulls behind him had the Force India not suffered a sensor failure in the brake-by-wire system that required him to re-set the system just as Ricciardo was looking to pounce.

Instead of being on the second step of the podium post-race, he – together with Massa – was in Montreal’s general hospital for a check-up after triggering the ‘black box’ g-limit sensor. His turning left in an apparent attempt at blocking Massa through the left-hand kink preceding turn one has earned him a five-place grid penalty for the next race.

Qualifying

Rosberg was deeply impressive all weekend. For one thing, he took pole position at what was always ‘supposed’ to be Hamilton’s track. No team-mate had ever got closer than 0.3s to Lewis between these walls in six previous events here and until Q3 on Saturday he always looked comfortably the quicker of the Mercs.

It wasn’t responding as well as most other cars to the super-soft tyre, though. Everyone else was finding that tyre to be around one second quicker over a lap than the soft, but on the Merc it was only around half that. The fronts tended to grain on the W05 before the lap was finished. But even giving 0.5s away it was still comfortably the fastest and pole was strictly a contest between Hamilton and Rosberg.

On the harder tyre Hamilton was much quicker. On the softer compound he seemed to create even more graining than Rosberg and so the margin was reduced. Hamilton was thread-the-needle precise and smooth in his shaving of the walls, Rosberg urgent and aggressive, appearing to have to work harder at it.

But through all the talk of Hamilton’s Montreal form, through all the practices and Q1 and Q2 with Lewis consistently quicker, Rosberg remained calmly resolved. On with the super-softs for Q3. A solid first run, fractionally slower than Hamilton in sectors one and two, but more than making up the deficit in the final sector – pressure to Hamilton duly applied. Repeat for the second run, clean and quick but nothing heroic. Hamilton, with the pressure on, tried to dig deep and came up against those same locking fronts at turn six. Trying yet-harder, he locked up again at turn eight. A Rosberg pole at Hamilton’s track.

There was similar transposing of forms into Q3 at Red Bull and Williams. Ricciardo didn’t get his lap together, Sebastian Vettel did and qualified third, two places up. Splitting them was the FW36 of Valtteri Bottas who strung it together better than Felipe Massa whose underlying speed had looked better up until that point.

The super-softs were tricky tyres over one lap – and over several of them the softs were much better. The low durability of the option tyre imposed a two-stop on pretty much everyone, especially when the track temperature climbed up to 47 degrees by the race start. But not Force India. Hulkenberg and Perez had qualified only 11th and 13th respectively, but the car was super easy on its tyres, particularly in Pérez’s hands.

The team has its own dedicated tyre department, with ex-Bridgestone tyre engineers and devotes a huge amount of care to understanding them – recall that it used to be able to run even the exploding 2013 Pirellis without problem. “We set the car up with tyre use very much in mind,” said Andy Green, “as we felt it would be advantageous if we could one-stop. That was always our intention.”

It was Hulkenberg’s turn to have first choice of tyre strategy – and his aggressive style made it obvious he should start on the prime, leaving the delicate option for when the car was lighter. For Pérez – not quite as quick as Hulk but with a style that takes far less from the rear tyres – it was an easy choice to do the opposite. It required a long run on the options when the car was heavy, “but Sergio can do that. We’ve seen it so many times,” said Green.

The race

A first-lap safety car that stayed out for seven laps helped with that too, made the one-stop even more secure, though it disadvantaged Hulkenberg relative to Sutil. Force India’s one-stop plan would come to have a profound impact upon the shape of the race.

Hamilton got off the line slightly better than Rosberg but the advantage of pole kept Nico just far enough ahead to squeeze Hamilton to the right as the track funnels through the kink of one into the heavy braking of two. A puff of smoke from briefly rubbing tyre sidewalls, with Hamilton having to get out of the throttle and slightly onto the grass between the turns – this all the opportunity the sharp Vettel needed to nip by for second.

Accelerating out of there – the engines gruff and aggressive as the sound bounced off the walls, the cars twitching under torque load through the uphill kink on the short run up to the chicane: Rosberg, Vettel, Hamilton, Bottas, Massa, Ricciardo and Jean-Eric Vergne’s Toro Rosso ahead of the two Ferraris of Fernando Alonso and Kimi Räikkönen.

At the back, Max Chilton got the Marussia very, very sideways on the entry to turn four. Team-mate Jules Bianchi was alongside him and had nowhere to go, reared up in the air as their wheels interlocked and was spun hard into the unyielding wall. Debris and spilt oil everywhere, two badly broken Marussias: safety car.

So the slow snaking pack saved fuel, circulating slowly around this ‘70s thin tarmac ribbon amid the parkland and water on a scorching Montreal day. On up through the dip beneath the trees, up to the slow left-right sequence of turns six-seven, onward down the kinking straight and the tricky, bumpy eight-nine, out of there and the run through the gears to the heavy braking zone for the turn 10 hairpin, the kink of 11 where the 2014 generation of cars can get out of shape under power at a point where the V8s were flat. Then the long 210mph straight and the challenge of 13-14 and the champion’s wall that lies beyond. Flat-out top gear, followed by tight second-gear turns requiring repeated heavy braking. The carbon brake discs remain hot and therefore oxydise quickly.

From the resumption of racing on lap eight Rosberg pulled steadily away from Vettel who with a Red Bull that was around 10kph down on end-of-straight speed to the Mercedes immediately had his hands full fending off Hamilton. Lewis went past a couple of laps later, a simple DRS move into the final chicane. Ricciardo back in sixth was feeling badly held up by the Williams pair ahead of him but lacked the straightline speed to be able to do anything about them.

Behind, Vergne was soon holding up a train comprising the Ferraris, Pérez and Jenson Button’s McLaren. Pérez’s super-softs had allowed him to pass his harder-tyred team-mate Hulkenberg who’d lost many places off the line.

On everything apart from Pérez’s car the super softs were beginning to wilt by around lap 13-14. Ricciardo initiated the stops at the end of 13, attempting to undercut his way past the white Martini FW36s. Williams responded by bringing in Bottas – as the driver ahead. Which rather hung Massa out to dry; consigned to wait a further lap after Bottas, he was certain to have been leapfrogged by Ricciardo – even had he not suffered the delay caused by the faulty wheel gun.

As it was, he lost a further couple of places too, but was in irrepressible form and soon fighting his way back through. Vettel was around six seconds behind Hamilton by the time he came in on the 15th lap for his primes. Alonso’s pace advantage over Vergne was such that he managed to pass him for seventh by stopping the lap after. But the Ferrari was already 20s off the lead. “We made some progress with the aero upgrades we brought,” said Fernando later, “though some of them we couldn’t run because the temperature was too high.”

Rosberg’s advantage on Hamilton was over two seconds as the Mercs made their stops on laps 18 and 19, rejoining still in the first two places – Rosberg coming close to losing it against the turn-four wall on his out lap. The Mercs were followed by the yet-to-stop Force Indias of Pérez and Hulkenberg and only then Vettel. The Force Indias were fast on the straights and Vettel slow, trapping him there and allowing Bottas and Ricciardo to be sitting close behind.

With the Mercs now on the non-graining prime tyres, Hamilton was much happier with the car’s balance and was soon eating quickly into Rosberg’s advantage. On the 21st lap he took 0.9s out of him, then 0.5s, then 0.6s. Nico eventually responded, but yet again was using more fuel than Hamilton.

By the 23rd lap the gap between them was less than a second and Hamilton was within DRS range. Two laps later Hamilton was slipstreaming Rosberg down the back straight, past the trap they flashed at 210mph, Lewis on the outside, Nico determined not to brake too early. “But the problem with that was we were running the brake balance further forward to protect the rears. So on that lap I just went straight on. I didn’t gain an advantage – well I did initially, but I slowed down in turns one and two. Thankfully the stewards saw it that way too. We’d been managing the brakes the whole race, because we knew it was going to be marginal.”

At one point Rosberg was on the radio asking what his ‘team-mate’s’ brake settings were and was told that he was further forwards than Lewis. Whilst it meant he was keeping stress off those overworked tiny rear discs, it also meant he wasn’t harvesting electrical energy as effectively.

Meanwhile Vettel tried a desperate pass on Hulkenberg at the hairpin, slid straight on and was repassed as they accelerated out of there. Massa, though, managed to make an easy move around the outside of Alonso through turns one and two, putting him back up to eighth, a few seconds behind Ricciardo who in turn was a few seconds back from Bottas, who was slowly catching the stymied Vettel.

Remarkably, Pérez was still hanging on in second place on his original set of super-softs. He was protected from having to over-stress them as team-mate Hulkenberg did a faultless job in holding off the faster cars. Force India’s one-stop strategy looked to be working just fine as Pérez finally came in for his new primes on lap 34 and rejoined 10th, but with no more stops to make, unlike the cars around him.

Hamilton had caught Rosberg but could do nothing about passing him. But worry was by now being transmitted through the Mercedes airwaves. They’d been keeping a close eye on the temperatures of the control electronics and were not liking the numbers they were seeing. The control electronics are essentially the ers system’s brain. Maybe it was the combination of such extreme heavy braking with the high ambient temperature, but within 30 seconds of each other just after halfway through the race, both W05s suffered a sudden and big loss of power as the ersK ceased to function.

Both drivers were given a litany of instructions in attempts at rebooting the electrical power systems, but to no avail. Rosberg and Hamilton were now around four seconds slower than before and around two seconds slower than the distant third-placed Hulkenberg who continued to thwart Vettel.

Ricciardo vs Vettel

Bottas came in as early as lap 35 for his second stop, an aggressively early attempt at undercutting past Vettel, forcing Red Bull to respond next lap. From right on the Force India’s gearbox Vettel’s in-lap was not particularly quick. Team-mate Ricciardo meanwhile, with a little bit of space where Bottas had previously been, was able to let rip and as Vettel came out on a crowded piece of track just behind Räikkönen’s Ferrari, he was unable to go particularly quickly at just the time Ricciardo was flying.

Danny’s in-lap was a full second faster than the compromised Vettel’s had been. He exited ahead just ahead of him. “Why did you not leave me out?” queried Seb. But it would have been pointless. They’d been forced into it by Bottas’ stop and by the fact that one-stopping Hulkenberg would likely be going for a long time yet, with Vettel unable to pass it. Circumstances had sidled up to Ricciardo and he’d leapt upon them. But now the Red Bulls were trapped once more behind Pérez’s Force India.

When Hulkenberg finally made his one and only stop on lap 41 it put Massa up to third ahead of Alonso, on 25-lap-old tyres. Ferrari brought Fernando in, but Williams – with the tantalising prospect of only two badly limping Mercedes ahead of them – decided it was going to attempt a one-stop with Massa.

Rosberg staggered into the pits on lap 43 for his second stop. There was a delay with the left front costing him a couple of seconds. Hamilton was in the lap after and his quicker stop saw him exit ahead of Rosberg. Felipe Massa’s Williams was leading the race. But only for a couple of laps; tyre wear had caused the team to reconsider the one-stop plan.

With more than a pit stop’s margin over Alonso, he was brought in on lap 47, rejoining seventh between Bottas and Alonso, but still less than 10s off the lead. Those ailing Mercs were back at the head of the field, protected from the faster Red Bulls and Williams’ by the old-tyred, one-stopping, fast-on-the-straight Pérez.

The stationary time in the pits proved fatal to Hamilton’s overheated rear discs. He slid straight on at the hairpin on lap 46, allowing Rosberg to retake the lead. Hamilton slipstreamed back ahead of him with DRS down the back straight, but found himself unable to slow down enough for the final turn, taking across the escape road and handing the place back.

After sliding straight on again later in the lap, he returned to the pits to retire. It was a blow to his title aspirations only if Rosberg was able to keep going. Remarkably, he was. The small difference in brake bias settings had proved to be the difference. Soon he had a tight queue up behind him comprising Pérez, Ricciardo and Vettel, with Hulkenberg not far distant from that and holding off Bottas, Massa and Alonso – and Button closing fast.

Rosberg was doing a stupendous job in a car missing 160 horsepower. He’d been told he needed to be quick in the first sector to give him the necessary gaps at the DRS detection point, preventing Pérez from being able to use the wing-stalling device down the back straight. Rosberg responded with a series of fastest sector times there, even if his overall lap was still a couple of seconds off his earlier peak.

“It was fine once I re-found my rhythm. I spent some time re-adapting all the braking points, which were very different because you are arriving with so much less speed. I knew there were quite a lot of cars behind me and I knew if one got me they’d all get me. So I was pushing like mad, doing qualifying laps all the time. I was feeling really good in the car, it had a good balance.”

Bottas’ tyres were 12 laps older than those on team-mate Massa’s car and he was instructed to pull aside to allow Felipe through in his chase of Hulkenberg’s fifth place. It didn’t actually happen that way – Bottas, with fronts already badly flat-spotted, locked up at the hairpin, allowing Felipe through. He then used DRS to put a pass on Hulkenberg at the end of the straight. He was flying and with 13 laps to go he was just seven seconds off the lead as he closed rapidly down on the Red Bulls, which were being held back to the pace of Pérez’s Force India.

The fresh-tyred Williams was taking over a second per lap out of them and with eight laps to go was with them. On the 64th lap, Vettel almost crashed into the back of his team-mate as they braked for the hairpin. He had to run out wide to avoid contact, allowing Massa to slip to the inside but with Vettel still just ahead. Felipe got out of the hairpin well and as Vettel’s Red Bull twitched through the kink of 11, the Williams began gaining as they built up speed down the long straight. But crucially, in the heat of battle, Felipe forgot to deploy his DRS. He would never get as good a chance again.

Meanwhile Pérez was in trouble with his rear brakes. With Ricciardo swarming all over him, it was a demanding thing to listen to instructions over the radio about how to reset the system. He was notoriously bad in these conflict-of-attention situations at McLaren – and it seems it’s still a trait, for it was at this moment that he lost second place, Danny simply driving around his outside into turn one, with the help of DRS.

It was all a bit marginal and, as he ran out wide partly onto the grass, locking up, so Pérez and Vettel almost collided in the concertina effect. But Danny made it stick. He was in second place. The Force India’s brakes were now working again, but Sergio was now in third, fending off Vettel.

Ricciardo meanwhile was quickly upon the limping Mercedes and with two laps to go was able to go by on the approach to the final turn. Vettel meanwhile got by Pérez a lap later at the same place and now Massa was swarming over the back of the Force India. Then the accident. Pérez was slow onto the pit straight, having got a messy run through the final turn. Massa opted for the inside. Pérez steered very slightly left, too late into the corner to block, with Massa already there.

Felipe in fact had begun to move right in anticipation of holding Pérez to the outside approach of the turn. Rubbing wheels in seventh gear, the cars speared off into the barriers with frightening violence, Vettel only just avoiding the Force India as it careered out of control. Mercifully both drivers were essentially unhurt. The stewards reviewed the evidence and concluded Pérez’s subtle steering left had caused the accident. Massa had braked 10 metres earlier than on the previous lap.

As this was happening Button was making up places, passing both Alonso and Hulkenberg at the hairpin. Ordinarily this would have put him sixth but the Massa/Pérez accident had gifted McLaren fourth ahead of Hulkenberg, Alonso, Bottas (who had been slowed by overheating brakes), Vergne, Kevin Magnussen’s McLaren and Räikkönen, who had earlier spun at the hairpin.

Daniel Ricciardo, Grand Prix winner, stood on the podium accepting all the champagne being sprayed upon him, perma-grin white teeth visible behind the spray. “It all happened so suddenly in the last couple of laps that it hasn’t really sunk in yet,” he said.