Will Power beat Alexander Rossi to victory at the Bommarito Automotive Group 500 at Gateway Motorsports Park, securing his third win of 2018 and keeping his Drivers' Championship hopes alive.
After qualifying for the 15th race of the season was cancelled due to poor weather conditions and heavy rain, championship leader Scott Dixon was handed pole position for the 248 lap race, starting ahead of Rossi and Josef Newgarden who lined up in third.
Power, who lined up in fourth place for the 500-mile race, took the lead on lap 150 after passing Dixon out on track before the race became a battle of different strategies, with a caution on lap 172 caused by Ryan Hunter-Reay creating a fuel dilemma.
Completing a splash and dash stop with less than 20 tours of the circuit remaining, Power stormed to victory, taking the chequered flag on lap 248.
Behind the Australian's silver #12 Penske, a key battle for the title emerged behind, with Rossi and Dixon battling for second and third using two clear-cut strategies, with the 2016 Indy 500 champion opting for a conservative approach to fuel management while Dixon emulated Power's race-winning strategy with a late-race stop.
Ultimately, it was Rossi who came out on top in the battle to finish in second place while Dixon crossed the line in third, 2.8092s adrift of Power.
Former champion Simon Pagenaud finished in fourth place and was followed by Zach Veach who finished in fifth after starting from 16th.
Spencer Pigot finished in sixth place and was followed by Newgarden who dropped from third to seventh in the race order, suffering from handling problems in his #1 Penske.
Ed Jones took eighth place as the final car on the lead lap and was followed by the Rahal Letterman Lanigan Racing pair of Takuma Sato and Graham Rahal who finished in ninth and tenth respectively.
IndyCar will return for the Grand Prix of Portland at Portland International Raceway on September 2.
