INDIANAPOLIS — Ryan Hunter-Reay held off a furious charge by Helio Castroneves to win the Indianapolis 500 for the first time.
The Andretti Autosport driver led the final four laps after taking the lead from Castroneves. Hunter-Reay, who won the 2012 Verizon IndyCar Series championship, was the first American to win the race since Sam Hornish Jr. in 2006.
"It's a dream come true, man, it hasn't even sunk in yet," said Hunter Reay, who finished third last year after losing the lead to winner Tony Kanaan on a restart just before a caution with three laps remaining. "I'm a proud American boy, that's for sure."
Castroneves finished second, followed by Marco Andretti, Carlos Munoz and Juan Pablo Montoya.
Kurt Busch finished sixth and immediately headed to Charlotte Motor Speedway where he will attempt to start tonight's Coca-Cola 600 and become the fourth driver to run the Indy 500 and Coke 600 in the same day.
It was the second-closest finish in Indy 500 history. Slingshot passing defined the final few laps as Hunter-Reay and Castroneves -- seeking his fourth Indy 500 win -- battled.
"There was no practice for it," Hunter-Reay said of the passing. "Never ran those lines at all. I didn't know if we had what it took; I did my absolute best. I knew we had a good race car; we didn't qualify well, started 19th. We did everything right today, and that's what it takes to win this race. I'm just thrilled."
IndyCar officials elected to stop the race to clean the debris from the track rather than have the race end under yellow (as it did last year).
"Certainly the stop like breaked the rhythm," Castroneves said. "It was close; a shame so close but you know it's Ryan Hunter-Reay's day. I want to give this to (team owner) Roger Penske so bad. It was a great fight. It was a great TV. I was having a great time. It's good when second sucks if you know what I mean."
After the longest green-flag start to an Indianapolis 500, the activity picked up significantly in the last 35 laps with a flurry of lead changes and caution flags.
Scott Dixon crashed on Lap 169 and capped a miserable day for team owner Chip Ganassi, whose four cars all suffered problems in the race.
The caution flag didn't fly for the first time until Lap 150 for a spin by Charlie Kimball, the longest green-flag stretch in the history of a race that started in 1909 (the track's official records, however, date only to 1976). It was the fastest race to halfway in Indy 500 history. At 100 laps, the average speed was 211.871 mph, shattering the previous mark of 177.687 that was set last year in a race that also featured a record 68 lead changes.
Even without a plethora of wrecks, several contenders still suffered problems, most of which were self-inflicted.
Defending winner Tony Kanaan's hopes of becoming the first repeat Indy 500 winner since Helio Castoneves (2001-02) were dashed by the first pit stop.
An apparent battery problem in Kanaan's No. 10 Dallara-Chevrolet stranded him in the pits, dropping him 18 laps off the pace and ruining an attempt at winning the Indy 500 in consecutive years with different teams (he moved to Target Chip Ganassi Racing this season after leaving KV Racing Technology).
Team Penske teammates Juan Pablo Montoya and Will Power were assessed pit speeding violations making stops with less than 75 laps remaining. Montoya was leading by 35.128 seconds when he pitted for Lap 131 and was penalized during a four-tire stop. It was reminiscent of the Brickyard 400 in 2009 when the Colombian dominated by leading 116 of 160 laps but finished 11th after being penalized by NASCAR for a pit speeding penalty.
Graham Rahal also was sidelined during his first pit stop by electrical problems in his Honda engine. He finished last after retiring on the 44th lap.
"The engine keeps shutting off, and you can't race like that," said Rahal, who has finished outside the top 10 in six of seven starts at Indy. "Our luck has been brutal here. This team is made up of champions, everyone is going to try very, very hard to try to improve. Today is just not our day."