Brazil's Helio Castroneves edged New Zealand's Scott Dixon by one-thousandth of a second to win Sunday's Indy 300 in the closest finish in IndyCar history but Dixon took the season points title.

Castroneves, who started last in the 28-car field after his qualifying run was thrown out by race officials, denied Dixon a record seventh race victory of the season in a tremendous run from the rear.

But Dixon, who began the day with a 30-point lead, needed only to finish in the top 10 to claim the crown even with a Castroneves triumph.

So by finishing second he claimed the one million-dollar bonus and his second series title, the other coming in 2003, by 17 points.

"What a great day," Dixon said. "I still can't believe it."

Dixon was only two turns shy of claiming the season prize a year ago at this same Chicagoland Speedway oval but he ran out of gas on the final backstretch and Scotland's Dario Franchitti sped past him to win the race and the crown.

The only other IndyCar driver to win after starting last was American Buddy Lazier at Phoenix in 2000.

Dixon did not lead until only 15 of the 200 laps remained after fading as far back as 11th in the middle of the race.

"We were trying to work out were where we needed to be and I think I got a little complacent in the middle there," said Dixon. "We got shuffled back."

"We tried everything to win. We did everything we could," Castroneves said. "Scott Dixon and those guys, they had a little better luck and they wound up winning the championship. Congratulations to them."

Australian Ryan Briscoe was third followed by Brazil's Tony Kanaan, Aussie Will Power and England's Dan Wheldon.

Indy-car racers will compete next month in a non-points event in Australia.