After parking in Victory Lane, Alexander Rossi removed his helmet and sat motionless in his race car for a moment, seemingly needing to fully grasp what had just happened.
And why not? Rossi, 24, had won the 100th Indianapolis 500 as a rookie after a stunning turn of events in the closing laps.
The native of Nevada City, Calif., inherited a sizable lead after front-runners Tony Kanaan, Josef Newgarden and Carlos Munoz were forced to pit for a splash of fuel.
Rossi's car was running out of fuel on the final lap, and he slowed sharply as he approached the checkered flag at Indianapolis Motor Speedway.
As team co-owner and race strategist Bryan Herta asked Rossi to keep saving fuel and told him he led by half a lap, Rossi's final lap was 179.784 mph — more than 40 mph off of the normal pace and a speed that would have been considered slow at the 21/2-mile Brickyard well before he was born in 1991.
But Rossi, who last pitted on Lap 164 and stretched his last tank of fuel 36 laps, had just enough speed to become the first rookie to win the 500 since Helio Castroneves in 2001.
"I just can't believe that we've done this," Rossi said after taking the winner's traditional drink of milk. "I'm just so thankful."
Munoz, a teammate of Rossi's, finished second. Newgarden was third and Kanaan, who won the Indy 500 in 2013, finished fourth.
"I really think we had a shot," Newgarden said. "It just didn't fall our way."
The low-key Rossi benefited from rivals' fuel-mileage woes, but his victory was not an accident.
Rossi initially set his sights on Formula One, and he reached that circuit in the final five races of last season for the Manor Marussia team. But after failing to secure a seat for this year, Rossi moved to IndyCar.
He started 11th in the 33-car field and, at one point, recorded the fastest lap of the race at 225.288 mph. He also stayed near the front until he could exploit the fuel-mileage battle.
"You can't undervalue what he did all month," Newgarden said.
Still, Rossi "had never seen this place until like a couple of months ago," team co-owner Michael Andretti said. "He really went to school and used his teammates and learned every day throughout the month."
Kanaan, Newgarden and Munoz kept swapping the lead in the final handful of laps before they all stopped for fuel. Munoz was openly emotional as he got out of his car after the race.
"It's really heartbreaking, to be honest," said Munoz, a runnerup at the Brickyard for the second time. "The reason is because I think we had a car to win. I'm not saying we should have won the race definitely because we had the best car, I just think we had a car that could have won."
As in recent years, the racing was close. There were 54 lead changes, and the top six or seven cars often were separated by less than two seconds.
One of the largest Indy 500 crowds in recent memory, more than 300,000 and perhaps close to 400,000, celebrated the race's centennial.
"I am humbled to experience this atmosphere today at this place that is packed," Kanaan said, adding that he also drove "the best race of my life" despite finishing fourth, "probably even better than when we won in 2013."
Pole-sitter James Hinchcliffe, racing a year after his near-fatal practice crash at Indy, finished seventh after leading 27 laps.
There were several accidents, but no drivers were injured. Defending race champion Juan Pablo Montoya finished last after he made contact with the outside wall on Lap 64.
Just past the halfway point, Townsend Bell and former Indy 500 winner Ryan Hunter-Reay, who were battling for the lead at the time, collided while leaving pit row and ruined their chances at winning. Hunter-Reay led a race-high 52 laps but finished 24th.
St. Petersburg resident Sebastien Bourdais was fourth on Lap 198 before having to stop for fuel; he finished ninth.
Rossi said it was "no secret" that his "goal was to get to Formula One" but that he was "ecstatic" to be in IndyCar instead, especially after winning the 500.
"It's obviously a huge honor and privilege, something I'm going to carry with a great sense of responsibility," he said.
Though F1 remains elusive, Rossi added, "I think it worked out just fine at the end of the day."