Five-time champion Dixon gave Newgarden a push after benefitting from a late caution and rallied to finish second. Dixon, who has earned seven top-five finishes in Iowa, was joined on the podium by defending race champion James Hinchcliffe. Simon Pagenaud was fourth, followed by Spencer Pigot and Alexander Rossi.
The affable Newgarden was a bit testy after Saturday's qualifying despite earning third spot on the grid.
"I was a little down [on Saturday]. I thought we had the pole car and we didn't get it right," Newgarden said. "I was so focused on making sure we got it right."
Newgarden pushed past teammate Will Power just ahead of a 25-minute red flag for rain and was never seriously threatened after that. When his team nailed his final pit stop with just under 50 laps left, the race was all but over — except for Dixon's late manoeuvring.
Dixon might be a long shot for a sixth title but showed yet again why he's one of the best drivers IndyCar has ever seen by reaching the podium with a car he seemingly fought all night.
Dixon, who at one point was 16th and a lap down, got within three seconds of Newgarden down the stretch on a night when the track temperatures were about 20 degrees cooler than the teams expected.
Dixon has either won or finished second 90 times in his career.
"Holy smokes. We were in second. I thought we were in 22nd," Dixon said. "It's a huge credit to the team. They definitely pulled one out there."
- AP
