INDIANAPOLIS — Alexander Rossi’s motorsports career path took a dramatic left turn Sunday, when the wannabe Formula One driver emerged as the unlikely rookie winner of the 100th Indianapolis 500.

Competing in only his second oval-track race, Rossi squeezed 36 laps/90 miles out of his final tank of fuel around the 2.5-mile Indianapolis Motor Speedway en route to his first Verizon IndyCar Series victory in his sixth start.

“It won’t sink in for a while. I don’t want it to,” said Rossi, driver of the No. 98 NAPA Auto Parts/Curb Honda. “I want to enjoy the moment, enjoy it with the people around me. It’s obviously a huge honor and privilege, something I’m going to carry with a great sense of responsibility.”

Rossi’s engine began sputtering for lack of fuel exiting Turn 4 on the race’s 200th and final lap, as Andretti Autosport teammate Carlos Muñoz began to whittle-down a 13.4-second gap. Rossi’s final lap averaged 179.784 mph — nearly 40 mph slower than Muñoz. With team co-owner/strategist Bryan Herta reminding him to save every drop, Rossi crossed the Speedway’s famed Yard of Bricks 4.4975-seconds ahead of Munoz.

“It was close obviously, close for comfort,” said Rossi, a 24-year-old native of Nevada City, California. “I was really focused on taking it one lap at a time. The emotional rollercoaster of this race is ridiculous. There were moments where I was stoked, moments where I was heartbroken, moments where I was stoked again. I need to see a psychiatrist after this.”

Rossi, the 10th rookie to win “The Greatest Spectacle in Racing,” was among 13 drivers accounting for 54 lead changes, second only to the 68 lead changes in 2013.

Most of the leaders, including Rossi, pitted during the sixth and final caution period on Lap 164 knowing they would likely not have enough fuel to go the distance. Rossi, Muñoz and eventual third-place finisher Josef Newgarden of Ed Carpenter Racing engaged in a rapid-fire round of lead-swapping over the final 17 laps before a sellout crowd of over 300,000.

Newgarden, driver of the No. 21 Preferred Freezer Chevrolet, pitted for fuel on Lap 195, moments after Muñoz passed him for the lead in Turn 1. Muñoz then pitted for a splash of fuel on Lap 196, handing the lead to Rossi with Herta in his headset.

“I’m still on the last lap actually with Bryan yelling at me,” said Rossi, who qualified 11th and led 14 laps. “He’s like, ‘Pull the clutch in and coast!’ I’m like, ‘What? OK.’ ”

Muñoz, a native of Colombia, placed second for the second time in four Indy 500 starts. “Half a lap short. That’s what it took,” said Muñoz, driver of the No. 26 United Fiber & Data Honda. “I don’t know how my teammate did it without stopping. If I’m honest, I want to know what he did.”

In his only previous oval-track event, Rossi started and finished 14th on the 1-mile Phoenix International Raceway on March 2. “He honestly had no idea,” said co-owner Michael Andretti, winless in 16 career Indy 500s.”He was 100 percent Europe, the way he was training and everything. Impressive. Really impressive.”

Andretti signed Rossi as his fourth driver on Feb. 23, following Andretti Autosport’s merger with Bryan Herta Autosport. Rossi became available after failing to secure one of two seats with the Manor Marussia Formula One team during the offseason. On March 9, however, Manor signed Rossi as its reserve and test driver.

“I can certainly say I’m not in a grand prix car anytime soon,” said Rossi, who watched last year’s Indy 500 from an American-themed sports bar in Monaco. “I’m a reserve driver. I sit around and pretend to look important. There is no driving involved. I drive to the track in a rental car.”

On Sunday, Rossi drove into open-wheel racing history as a “Legend of The Brickyard.”