Supercars great Scott McLaughlin has been left heartbroken after he crashed out of the Indy 500 on the warm-up lap.

One of the race favourites, he was warming up his tyres when he lost control and hit the inside wall — causing enough damage to be immediately ruled out of the race.

WATCH THE VIDEO ABOVE: Supercars great heartbroken after inexplicable Indy 500 crash on warm-up lap.

Know the news with the 7NEWS app: Download today

McLaughlin was plainly devastated after having crashed in the final round of qualifying last weekend.

He tried to describe his latest incident as a “rookie” error but simply could not explain it.

“Just really upset for my team,” he said after leaving the medical centre for a check-up.

“They built me a fantastic car again. I’m really sorry to my sponsors, my fans, my family. I don’t know what happened.

“I can’t believe we’re out of the race. I just had so much hope today. It’s by far the worst moment of my life.

“I know it’s probably dramatic but it’s just like... I put so much into the race. Everyone does. And I didn’t even get to see the green flag.”

Making matters worse for his controversy-strewn Team Penske outfit, two-time reigning Indy 500 winner Josef Newgarden bowed out with 66 laps to go because of a fuel pressure problem.

“It’s tough to not have a shot at the end,” Newgarden said.

“I just wish we had a chance to fight for it.”

Alex Polau, the dominant driver this season, made history as the first Spanish man to win the Indy 500.

He passed his former teammate Marcus Ericsson with 16 laps left after deciding he had had enough of sitting second and saving fuel.

“I cannot believe it. What an amazing day. What an amazing race,” Palou said.

“I cannot believe it. It was tough. Tough conditions out there, especially if you were like, third or fourth in the pack. Even leading, the fuel consumption was super high, so they didn’t want me to lead. I wanted to lead, honestly, so yeah, made it happen.”

Team Penske owner Roger Penske, who also owns IndyCar, Indianapolis Motor Speedway and the Indy 500, delivered the message for drivers to start their engines after the most dramatic of weeks.

He had been scarce in public since qualifying weekend, when the cars of Newgarden and Australia’s former winner Will Power were found to have an illegally modified part.

Both were penalised and sent to the rear of the 33-car starting grid.

Penske went even further after the second scandal to engulf his team in just over a year, firing team president Tim Cindric and Team Penske officials Ron Ruzewski and Kyle Moyer, who had served as the strategist on McLaughlin’s car.

McLaughlin did not have the illegally modified part on the car that he wrecked in the final round of qualifying.

Power finished 19th in the 109th running of the Indy 500.

The start was delayed then a cloud of light rain that passed over the speedway, where a crowd of about 350,000 people had arrived early and packed the sold-out grandstands.

Trucks with huge dryers were sent onto the track, and it was declared ready by race control after a delay of about 35 minutes.

Penske received a warm ovation when he finally stepped to the microphone and delivered the starting command.

- with 7NEWS