AP photo by Darron Cummings / Andretti Autosport driver Colton Herta race Saturday's IndyCar Grand Prix on the road course at Indianapolis Motor Speedway. Herta endured a wet, challenging day to earn his seventh career win but first in 10 starts at IMS.

INDIANAPOLIS — As Colton Herta set up his winning pass Saturday, all he could see were red flashing lights.

He still charged forward.

The Andretti Autosport driver quickly darted to the inside of Arrow McLaren SP's Pato O'Ward on a late restart, took the lead for good with nine laps to go, and beat Simon Pagenaud to the finish line by 3.0983 second to win a wild, wacky, wet IndyCar Grand Prix.

"Pure talent," Herta joked when asked how he persevered for his first win of the season despite the incredibly challenging weather conditions on the road course at Indianapolis Motor Speedway. "The most interesting thing is you never have a car that handles great in the wet and great in the dry, but it happened today."

Getting to victory lane certainly wasn't easy for the 22-year-old Californian, who earned his first Indy win at IMS in his 10th series start at the venue. He also became the first Honda driver to reach victory lane this season.

On Saturday, he and his team made all the right calls on the way to Herta's seventh career victory.

After qualifying 14th on the 27-car grid, he made the gutsy choice to switch from rain tires to dry tires just three laps into the race. While he initially struggled to keep the cold tires on the track and nearly spun out on the fourth lap when he got sideways in the 10th of 14 turns on the 2.439-mile course, Herta never flinched.

Somehow he hung on, quickly taking the lead and taking advantage of a move that allowed him to go from 15th to first. He stayed near the front of the pack the rest of the race, leading 50 of 75 laps in a two-hour event that had just 53 minutes, 22 seconds of green flag time.

It came on a day when race strategists and drivers were constantly changing plans because of rain or the threat of it. And even when it appeared Herta made the wrong choice — like running on dry tires after Alexander Rossi had made an early switch back to rain tires — things worked out.

"What I said is with the track conditions right now it's probably wets, but it you think it's going to be dry we'll go with slicks," Herta said referring to the first of two late pit stops. "Immediately when I got out there, I knew it was going to be tough, so we came back in. Luckily, everybody followed our lead and did the wrong thing, so we didn't lose too many spots."

Pagenaud and Team Penske's Will Power, who started in pole position, struggled to navigate the spray coming off the other cars. Neither could see well enough for long enough to catch Herta in the first IndyCar rain race with the aeroscreens.

Still, the two three-time race winners and former teammates felt as if they had also accomplished something. Pagenaud, the French driver who will turn 38 on Wednesday, gave Meyer Shank Racing its best finish of the season.

"That was nuts. The racing was phenomenal and the strategy was the name of the game today," he said. "Sometimes second feels like a win. I would have liked to win today, but we'll probably celebrate tonight like it was a win."

Power took the series points lead away from 2021 champion Alex Palou, and his third-place finish was the best result Saturday for Penske.

"At the end, you couldn't see. I can't imagine being back in 10th or something," the 41-year-old Australian said. "Pretty crazy day, one to keep you on your toes and when to pick the right tire and don't overdo it. Just survival."

Race organizers knew weather would be a factor. They moved the start time up about 30 minutes with the hope of a wet track. Instead the start was delayed — first because of nearby lightning in the area and then because of a steady light rain.

The cooler, damper surface changed everything. There were spins and crashes, even cars struggling to stay in line under caution. And nobody, not even the series' top names, were immune.

Penske scrambled to get two-time series champ Josef Newgarden back on the course after his car was damaged in a crash on the 17th lap. Power lost three spots on the first lap. Scott McLaughlin, Penske's third driver, lost the lead when he spun under caution.

Six-time series champ Scott Dixon, the 41-year-old New Zealander who drives for Chip Ganassi Racing, ran out of fuel on pit lane. Dixon's teammate, Palou of Spain, fell out of contention when he, like Rossi, made the move back to rain tires too early.

O'Ward and teammate Felix Rosenqvist got tangled up in the first turn on the 42nd lap.

"I knew we could do it," Herta said. "Did I think we were going to win today in a normal dry race? No, probably not. But we kind of adapted pretty well. It was a lot of fun."

Teams and drivers aren't going anywhere.

Next up is the series marquee race, the Indianapolis 500 on May 29. Everyone gets a two-day break while the track is converted from a road course to the more traditional oval. Practice starts Tuesday, and two days of qualifying are set for next weekend.