Scotland's Dario Franchitti passed New Zealander Scott Dixon to win the Indy 300 in Chicago and capture his first ever IndyCar Series title.
Franchitti will reportedly move to Nascar next year
Dixon was leading the race but ran out of fuel on the final lap, allowing Franchitti to pass him on the outside and take the final race of the year.
Franchitti, winner of the Indianapolis 500, is reportedly set to jump to the Nascar stock car series next season.
He started the race with a three-point lead atop the standings.
He finished it with 637 points, with Dixon 13 points behind.
"Coming down the last lap I knew what I had to do. I drafted him out as well as I could, just pulled out going into turn three," said Franchitti.
"And as I pulled out I saw his car twitch and with him losing the drive, he shot up the track. I had to avoid him and went higher than I would have liked.
"Once I corrected that, I knew that the race and championship were ours."
Afterwards, Franchitti climbed out of the car and took a moment to collect his thoughts.
"At that point there was a lot of stuff going on in my head," he admitted.
"I was thinking of a lot of different people, some people who are no longer with us.
"That was just a point to take stock a little bit there and think of what we had achieved. It was nice to have that minute just to compose myself."
Sam Hornish was third across the finish line, followed by Brazil's Helio Catroneves and Scott Sharp.
Brazilian Tony Kanaan, the only other driver with a chance to win the title on Sunday, finished sixth.