Colton Herta overcame changing weather conditions and several on-track incidents to what turned out to be a long the GMR Grand Prix.
It is Herta's first of the season and seventh of his career.
It was especially impressive considering he started 14th on the grid, although it is impossible to deny there was at least some luck involved with so many variable conditions at play.
"This is the hardest race I think I've ever done," Herta said. "Wet to dry, dry back to wet.
"Thank you so much for the Hoosiers for sticking around. I know you're used to this weather, so thank you very much. Love you guys."
The race quite literally went the distance. Even though the full allotment of 85 laps was not completed, it had to be called during a late caution period because it had reached its two-hour runtime limit.
The ever-changing weather conditions meant tyre strategies were constantly in flux and allowed for a lot of movement in the field.
Simon Pagenaud started 20th and was able to climb to a season-high finish of second, with Will Power completing the podium to take the points lead in the IndyCar Series.
As a brief indication of the chaos during the race, there were 10 lead changes involving six different drivers and eight caution periods that last for a cumulative 31 laps.
Pre-race rain meant that everyone began with grooved tyres but it took just two laps for several drivers, including Herta, to make the call to switch to slicks.
There was near-constant chatter between the pit lane and the drivers as clouds rolled in and out and rain started and stopped all afternoon.
Colton Herta's play for the lead
The turning point came around lap 42 when some more threatening clouds and a bit of drizzle arrived
Some drivers, including race leader at the time Marcus Ericsson, decided to make an early pit for rain tyres but it stayed dry, allowing Herta to pass him three laps later.
With more rain falling and a caution on lap 60, the entire grid came in for wet tyres except for Pato O'Ward, Scott McLaughlin and Romain Grosjean.
The trio move out in front but when the rain came down hard in the 66th lap, Herta was easily able to pass the slick-tyred leaders.
"It was treacherous at the end," Pagenaud said. "You've got to say congrats to Colton because it was really tough to finish the race. We made the right calls on the tires. It was tricky. It was really tricky to decide."