Scott Dixon has finished ninth at the crash-marred penultimate round of the IndyCar series to maintain a slim chance of winning his fourth title.
Dixon was one of 12 different drivers to lead at various stages of the ABC Supply 500 at Pocono Raceway in Pennsylvania.
He slipped back in the field over the closing laps, leaving him third overall and 47 points behind Colombian leader Juan Pablo Montoya, who was third, and 13 behind second-placed American Graham Rahal.
Double points are on offer in the final race, Sunday's Grand Prix of Sonoma in California, meaning Dixon could add to series crowns in 2003, 2008 and 2013 for his Chip Ganassi Racing team if results go his way. The top six drivers are still in contention.
Ryan Hunter-Reay won under the 12th yellow flag of the race with US compatriot Josef Newgarden claiming second place.
Half of the 24-strong starting grid didn't make it to the finish line in Pocono, with 12 cautions required.
The most serious incident came on the first lap when British driver Justin Wilson was struck in the head by a piece of debris and airlifted to hospital.
Juan Pablo Montoya (Colombia) 500 points 1, Graham Rahal (USA) 466 2, Scott Dixon (NZ) 453 3, Will Power (Australia) 439 4, Helio Castroneves (Brazil) 423 5.