It was his second victory at the Brickyard — the first was 15 years ago.
Montoya started 15th and drove from the back of the field. Early on in the race he was forced to make an unscheduled pit stop to repair his right fender after he was hit from behind. That put him last among the 30 cars left in the race. Montoya made up the time in less than 30 laps.
He held off fellow Team Penske racer Will Power in the final two laps of the race. Power came in second, losing by a car length.
"It was awesome," said Montoya, 39, after placing the winner's wreath around his neck, taking the traditional chug of milk and letting it dribble down his chin, according to Indycar.com.
"This is what racing in Indy car is all about, racing down to the wire. These guys, Team Penske, did an amazing job. I had the feeling that I had a really good car, but that fight at the end was really, really hard. All the way down to the wire. This is pretty awesome."
The victory extended Roger Penske's record of Indy 500 victories to 16, and Montoya is the 11th different winner for Team Penske.
Montoya has said his victory in 2000 was pretty easy. He lead 167 of the 200 laps.