Scott Dixon claimed a dominant victory in Sunday's IndyCar race at Watkins Glen International, while Simon Pagenaud stole a march in the hunt for the title after a heavy crash for team-mate Will Power.
Chip Ganassi Racing driver Dixon had topped all three practice sessions and qualified on pole position for the penultimate round of the season.
Dixon managed his race well and, when Power crashed with Charlie Kimball on lap 39, the majority of the final pit stops took place under yellow flag conditions.
By the end of the race, Dixon had led for 50 of 60 laps and was 16.5 seconds clear of Josef Newgarden at the chequered flag.
By the end of the first phase, Power was second ahead of Team Penske team-mate Pagenaud - who leads the series - but both men saw their progress halted having not pitted before a yellow flag for a tyre blowout for Mikhail Aleshin.
In a bid to get through the pack Power was aggressive, but he spun out of the race after an ambitious move from Kimball saw the drivers collide.
Power was cleared by the medical centre, but was not given the green light to continue racing.
Pagenaud could only finish seventh, but he now takes a 43-point lead over Power into the season-finale at the Grand Prix of Sonoma on September 18 where double points are available.