Marcus Ericsson has been left furious after losing the lead on the final lap of the Indy 500, criticising officials for an "unfair and dangerous" end to the race.
The Chip Ganassi Racing driver was in the lead when a third red flag was thrown with two laps remaining, leaving Ericsson on the verge of becoming the first driver to secure back-to-back wins in the 'greatest spectacle in racing' since Helio Castroneves in 2002.
But race officials opted to send the drivers out for a thrilling one-lap shootout for victory - an unusual decision given cars usually perform an out-lap and warm-up lap at the Indianapolis Motor Speedway before going back to green-flag conditions.
The upshot of the decision was Ericsson was forced to defend the lead from Team Penske driver Josef Newgarden, who eventually stole the victory with a pass into Turn 3.
A clearly irritated Ericsson, who competed for Caterham and Sauber in F1 before moving Stateside, told NBC Sports: "It was an unfair and dangerous end to the race.
"I don't think there was enough laps to do what we did. We have never done a restart out of the pits, we don't get the tyres up to temperature.
"I think we did everything right, I am very proud of everyone at Chip Ganassi Racing. I did everything right behind the wheel, an awesome last restart, I think I caught Josef off-guard and built the gap and kept the lead into Turn 1, which nobody had all day.
"I just couldn't hold it on the back. I was flat. Congratulations to Josef, he is a worthy champion, but I am very disappointed by the way that ended, I don't think that was fair.
"We won that race and then everything got taken away from us.
"It is what it is. I think I did everything right on that restart, it was awesome but just not enough with what we had.
"It is tough to swallow for sure."