With five laps remaining, Scott Dixon, who had led more than half of the race, dived into the pits to refuel. Dan Wheldon and Tony Kanaan, running second and third at the time, followed Dixon. That put Castroneves into the lead, but he slowed dramatically heading into the third turn on the 198th lap of the 200-lap race, and Patrick took the lead and the historic victory.

Castroneves said he didn’t know Patrick was passing him for the lead, but admitted he didn’t have enough fuel to battle her late in the race.

“She passed me fair and square,” Castroneves said. “I didn't have enough fuel even if I wanted to fight with her, and today I guess it's part of history again.”

Michael Andretti, who hired Patrick away from Rahal Letterman Racing after the 2006 season, praised his driver and acknowledged the historical significance of her win.

Danica Patrick and her AGR crew played strategy to perfection to take her long awaited first IndyCar win. (LAT photo) » More Photos

“Danica is such a fantastic person, and I’m thrilled for her that the monkey is finally off of her back,” Andretti said. “We have all believed in her and she proved today that she is a winner. Frankly, I think this is the first of many.”

Patrick’s dad, T.J. Patrick, who discovered his daughter’s ability to drive go-karts and spent more than a decade helping her pursue big-time racing, fought back tears as he hugged her after the race.

“This is the best day of my life,“ T.J. Patrick said. “I’ve dreamt about it. I’m just so proud of her. She gets a lot of grief for it, but she just proved to everyone that she can win. There’s a lot more to come.”