Will Power in the No.12 Verizon Business Team Penske Chevrolet made it two wins in two races at Iowa Speedway for Roger Penske.
Power came from 22nd on the grid to claim his second win of the season and his first oval victory for a number of years.
Alex Palou came home in second place and has seen his championship lead shrink to 35 points heading to Toronto next weekend.
Having won here last night, Scott McLaughlin completed the podium in third place just ahead of six-time series champion Scott Dixon.
Colton Herta came home in fifth place just ahead of Pato O’Ward and Josef Newgarden while Graham Rahal scored his best finish of the season in eighth place just ahead of Rinus VeeKay while Romain Grosjean rounded out the top ten for Juncos Hollinger Racing.
Santino Ferrucci in the No.14 Sexton Properties AJ Foyt Racing Chevrolet was 11th but has made or back to the top ten in the championship.
Linus Lundqvist was 12th just ahead of David Malukas and Nolan Siegel while Kyle Kirkwood was involved in a horrendous crash on the last lap of the race and was stuck in his car for a time as Ed Carpenter’s car landed on top of Kirkwood’s car. Both drivers were OK after Alexander Rossi ran out of fuel.
Christian Lundgaard was classified in 17th just ahead of Kyffin Simpson and Marcus Armstrong.
Pietro Fittipaldi was classified in 20th place just ahead of Sting Ray Robb who went upside down multiple times on the final lap of the race and waved his hand to show he was OK.
Ed Carpenter was classified in 22nd just ahead of Marcus Ericsson and Katherine Legge and Agustin Canapino while Felix Rosenqvist and Conor Daly rounded out the order in 27th place.
Next up is the race in Toronto.