Alexander Rossi wins the 2016 Indianapolis 500

In a shocker, Rossi becomes the first rookie winner of the Indianapolis 500 since 2001.

Alexander Rossi used fuel conservation to pull off a stunning victory in the 100th running of the Indianapolis 500 Sunday at Indianapolis Motor Speedway. The 24-year-old rookie had to slow considerably just to complete the final lap, coasting underneath the checkered flag ahead of Carlos Munoz and Josef Newgarden.

Rossi inherited the lead when leaders Munoz, Newgarden and Tony Kanaan all pitted over the final 10 laps. The native of California then went into fuel-conservation mode, running just fast enough to maintain his lead while not overextending his fuel tank. Rossi is the first rookie to win the Indianapolis 500 since Helio Castroneves in 2001.

"This is just phenomenal," Rossi said. "I had no idea I'd be in IndyCar, I had no idea I'd be in the Indy 500 and now I'm here. We've won and I'm at a loss for words. It will change my life for sure."

Munoz finished runner-up for the second time in four years, with Newgarden third and Kanaan fourth. Charlie Kimball was fifth.

"I cannot say I'm really happy, I'm just really sad and disappointed," Munoz said.

Several drivers gave the appearance as potential winners Sunday, only for strategy and misfortune to knock them out of contention.

In the early going, Ryan Hunter-Reay led 52 of the first 117 laps and maintained a consistent presence at the front of the field. But the 2014 Indianapolis 500 winner sustained damage when Townsend Bell, who led 12 laps, spun into Hunter-Reay during a pit stop damaging both their cars. Hunter-Reay and Bell drive for Andretti Autosport, as do Rossi and Munoz.

"We just screwed off this whole Indy 500," Hunter-Reay radioed to his team.

After Hunter-Reay and Bell fell down multiple laps following repairs, that opened for Helio Castroneves, Munoz, Kanaan and Newgarden over the second half. But Castroneves had to make an unscheduled pit stop for damage to his left-rear wheel cover, while Munoz, Kanaan and Newgarden couldn't save enough fuel.

All the while, Rossi continued to fly under the radar. He went the final 90 miles without stopping.

"I have no idea how we pulled that off," Rossi said. "We rolled the dice and we came through and made it happen."

JR Hildebrand finished sixth, pole sitter James Hinchcliffe was seventh, Scott Dixon eighth, Sebastian Bourdais ninth and Will Power completed the top 10.

Defending race winner Juan Pablo Montoya crashed out on Lap 64 in a single-car incident. Montoya got loose and spun completely around off Turn 2, smacking the outside wall and sustaining considerable damage. He finished 33rd.

"The car was really good and it felt okay," Montoya said. "I went into (Turn) 2 and got a big push and I got out of the gas and it just came around."

The 54 lead changes were the second-most in Indianapolis 500 history, trailing the 2013 race that featured 68 lead changes.