Ryan Hunter-Reay drove a perfect race at the California Speedway on Saturday night to win this year’s IndyCar championship after Will Power threw away his chances for the third year in a row.

Less than a quarter of the way through the 500-mile race championship leader Power tried to pass Hunter-Reay for seventeenth place only to lose control and spin into the wall, narrowly missing collecting his title rival.

“I just caught a seam,” said the disgusted Power. “The car was pushing there all night. It was pushing and pushing and caught a seam. It really caught me by surprise. It was the last thing I thought would happen. To make a mistake like that is bad.”

After forty-five minutes of repairs Power rejoined, running a dozen slow laps to try to add a few more points to his tally, but the car was too badly damaged to continue safely. Power admitted he must get his act together on ovals.

“I’ve had crashes on three of the ovals this year,” he observed. “That was a massive hit in the points. I’ve had three years winning the road course championship convincingly, so it’s very obvious where I lack.”

Meanwhile Hunter-Reay moved steadily through the field racing aggressively in close quarters on the high-banked oval. He needed to finish fifth to sew up the title and sealed his bid by taking fourth place in the closing laps to finish directly behind winner Ed Carpenter, Dario Franchitti and Scott Dixon. Hunter-Reay thus beat Power to the championship by just three points.

Hunter-Reay struggled to find speed in practice, qualifying seventeenth, but by half-distance he was up to seventh place with the championship within reach. As the race wore on oval specialist Carpenter began to assert himself duelling with Dixon, Franchitti and an impressive Alex Tagliani who charged into the lead before making his last top with 26 laps to go.

After the final round of stops Tagliani led from Sato, Carpenter, Franchitti, Dixon and Hunter-Reay. Sato and Carpenter duelled with Tagliani for a few laps before the French-Canadian – convinced he had the car to win – suffered an engine failure. Franchitti then took the lead and was in front when Tony Kanaan crashed with seven laps to go, bringing out the red flag for a short period to insure finishing the race under the green.

From the final restart Franchitti continued to lead chased by Carpenter, Hunter-Reay, Sato and Dixon. Going into the last lap Carpenter made a bold move to take the lead around the outside of Franchitti while Sato duplicated his performance at Indianapolis this year, spinning into the wall as he tried to dive-bomb Hunter-Reay and Dixon. So Carpenter scored the second IndyCar win of his career and first as a team owner after an excellent drive with Franchitti finishing second, Dixon third and Hunter-Reay fourth. Ryan could not believe he’d won the championship.

“We were struggling all weekend,” he said. “We were really in the woods. But through the first half of the race we kept making the car better and better at each stop and Michael did a great job on the radio. It hasn’t sunk in yet. I can’t believe it. My dream has come true.”

This is Andretti Autosport’s fourth IndyCar championship and first since 2007 with Franchitti. Hours before the start Michael Andretti announced that Hunter-Reay and he had agreed to a two-year contract extension through 2014, quelling rumours that Ryan was headed to Penske. It’s been a long and difficult road for Hunter-Reay but at 31 he’s finally arrived at the top of American open-wheel racing.