Defending champion Helio Castroneves won the 86th Indianapolis 500 race on Sunday.

The Brazilian became the first driver since Al Unser Snr in 1971 to win the race two years in a row.

"Oh my goodness," said Castroneves. "What a great deal. Thank God. We did it again. Awesome. Unbelievable. It's a dream come true."

With one lap to go, Tracy made his move to pass Castroneves.

But at the same moment Frenchman Laurent Redon and 1996 winner Buddy Lazier became entangled half a lap behind and crashed into the wall, bringing out the yellow flag.

Officials ruled that Tracy had passed Castroneves under the caution and gave the Brazilian the win.

Tracy's team immediately filed a protest.

"I feel I was ahead when the yellow came out," Tracy said. "I caught Helio on the last lap. They say it was under yellow.

"I thought it was green when I went past him. We will protest and see what happens."

Castroneves gambled on low fuel and thinning tyres, and finished the race with just 0.4 of a gallon of fuel remaining.

"I was holding my breath, for sure," said team owner Roger Penske said.

South African Tomas Scheckter, son of 1979 Formula One champion Jody Scheckter, and Brazil's Tony Kanaan both crashed while leading.

Newcomer Scheckter led at the halfway point, setting the fastest halfway pace in Indy history, before crashing out.

Results from 86th Indianapolis 500 (drivers US unless stated):

1. Helio Castroneves (Bra), 2 hrs, 59 mins, 51 secs
2. Paul Tracy (Can)
3. Felipe Giaffone (Bra)
4. Alex Barron
5. Eddie Cheever
6. Richie Hearn
7. Michael Andretti
8. Robby Gordon
9. Jeff Ward
10. Gil de Ferran (Bra)

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