Simon Pagenaud ended a personal slump in spectacular fashion by overtaking Scott Dixon with just over a lap remaining to claim victory on the Indianapolis Motor Speedway road course.

Pagenaud and Team Penske played the changing conditions perfectly, allowing the 34-year old Frenchman to end a 22-race winless streak that dated back to late 2017.

Expected precipitation arrived about a third of the way into the 85-lap contest, but the rain never fell hard enough to completely soak the track.

By then, pole man Felix Rosenqvist paced the first 15 laps, but the Swede lost the lead to his Chip Ganassi Racing team-mate Dixon’s Honda on a restart.

Dixon led until he pitted on Lap 27, elevating IndyCar championship leader Josef Newgarden to the top spot.

After starting 13th, Team Penske had strategically pitted Newgarden on Lap 16, and from the time Dixon stopped it was a question of who would benefit from the timing of the rain.

Newgarden led until Lap 39, when he stopped for another set of dry tyres, leaving Dixon with a five-second lead over Jack Harvey (Meyer Shank Racing Honda) and seven seconds over Pagenaud.

Dixon burned up his rear tyres, allowing his pursuers to close up. All three pitted on the 47th lap, with Pagenaud’s crew getting him out ahead of Harvey.

The rain picked up substantially around Lap 55, putting leader Newgarden in the position of trying to eke another handful of laps out of his fuel and tyres in order to make it to the finish with one more stop. He seemed to catch a break when his Penske team-mate Helio Castroneves spun exiting the pits on wets.

After the field packed up behind the Safety Car, everyone pitted on Lap 63. Newgarden’s crew lost control of a tyre, earning him a penalty that dropped the American to 15th place at the chequered flag.

Dixon rolled out to what looked like a comfortable lead, but Pagenaud soon started to mount a charge.

The 2016 IndyCar champion passed Matheus Leist with 10 laps to go, then hunted down Harvey and took over second place with an impressive move under braking into Turn 1.

While Pagenaud had used up all his push-to-pass, Dixon had 33 seconds remaining and a five-second lead, putting the win within sight of the New Zealander.

However, Pagenaud would not be denied, as he trimmed Dixon’s lead by almost two seconds a lap. On the penultimate tour, Dixon ran slightly wide exiting Turn 7, allowing Pagenaud to the inside.

The Penske Chevrolet held the favourable line through the subsequent right-left combo and emerged in the lead after a remarkable drive.

He crossed the line 2.05 seconds ahead of Dixon, with Harvey a career-best third.

“The whole race was amazing,” said Pagenaud after his 12th career IndyCar race win and third on the IMS road course.

“I thought, ‘What’s going on?’ I thought everyone was saving fuel because we were just so fast.

“That’s my third time winning the Grand Prix, so I’m equal with Will (Power).

“It’s awesome to keep it in the family with Team Penske.

“This is the sweetest win I’ve ever had, I guess.

“I know what I’m worth; I’ve just got to get everything right, and this weekend, slowly but surely, we got there.

“The stars didn’t always align before but the performance was always there this year.”

Dixon finished second in the Indianapolis for the third consecutive year. He also has three second-place finishes in 2019.

He said he lacked front end grip in the closing laps, hindering his efforts to keep Pagenaud behind.

“It was generally a pretty good day,” Dixon reflected.

“Conditions were very tricky all day, but it was a lot of fun.

“I kind of knew with about 10 laps to go that we were going to get hosed and that I was going to be struggling with the front end.

“I don’t know why the balance went that way, but we just had no front grip.

“It felt like we needed about six turns of front wing.

“Obviously it sucks to lead that many laps (39 of 85) and come up short, but big congrats to Simon. It’s nice to see him back in Victory Lane.”

Harvey, who is running a 10-race schedule for Meyer Shank Racing, enjoyed his best result by far in the IndyCar Series.

The 26-year old Englishman prioritised fitness to lose 10kg prior to the start of the season, and he has posted three top 10 finishes already this year.

“I knew this weekend could happen eventually,” exclaimed Harvey.

“You can see how hungry these guys were to get a podium so you can imagine what it will be like when we get a win.

“Hopefully this is a springboard that gives us some momentum for the Indianapolis 500 and beyond and catapults us into a full-time drive.”

Three-time Indianapolis road course winner Power struggled for pace throughout the race and finished seventh.

Despite the 15th place finish, Newgarden retains the IndyCar Series lead by a slim six-point margin heading into the Indianapolis 500.

Dixon took over second place in the standings as Alexander Rossi had a disastrous day, finishing in 22nd place in his Andretti Autosport Honda.

Rossi was bumped into the wall by rookie Patricio O’Ward in the run to the start and he lost four laps while his rear suspension was repaired. He fell 36 points behind Newgarden.

It was a forgettable event for Andretti, with Zach Veach’s 12th place as the team’s best result.

Attention now turns to the famous Indy oval, with Indianapolis 500 practice set to start on Tuesday (local time).

Race results: Indianapolis Motor Speedway (road course)

Race winner: 85 laps
(C)hassis: D=Dallara | (E)ngine: C=Chevy, H=Honda | (T)yre: F=Firestone

Series points