Donohue passed Ganassi driver and NASCAR Sprint Cup Series star Juan Pablo Montoya with 39 minutes remaining and finished just 0.167 seconds ahead of Montoya to make it the closest margin of victory in event history. The previous record for closest finish was in 2000 with a margin of 30.879 seconds.

"I'm just proud that I can deliver the goods for the team," Donohue said. "I was just the guy who got to be able to do it. If you look at the practice time, we're all right there. So I think that's what makes this team as strong as it is, to be honest with you. And that's why they chose Buddy and Antonio to join us. The same thing happens all year long between Darren and I. Doesn't matter who is in the car. That's what the car's got. We're really lucky that way."

In the twice-around-the-clock event, Donohue shared driving duties with Antonio Garcia, Darren Law and 2004 Indianapolis 500 winner Buddy Rice in the No.58 Porsche Riley for Brumos, while Montoya, also a former Indy 500 winner (2000), teamed up with Memos Rojas and Scott Pruett in the No.01 Lexus Riley for Ganassi.

"I was actually surprised we even fought for the win, to be honest," Montoya said. "I drove my butt off. I knew if I would get any traffic in the backstop I was done. And I did, and I was done. And it didn't matter how many times they made mistakes. And they just kept driving off and driving off for me, even when I was in the draft."

Joao Barbosa drove Brumos' second team to a third-place finish as he crossed the line 5.504 seconds behind Donohue. JC France, Hurley Haywood and Terry Borcheller also drove that car.

Max Angelelli was fourth in the No.10 SunTrust Racing Ford Dallara, co-driven by Wayne Taylor, Pedro Lamy and Brian Frisselle.

This year's Rolex 24 at Daytona also featured the most finishers on the lead lap, as the top-four finishers covered 735 laps or 2,626.6 miles.

Scott Dixon, the reigning IndyCar Series champion, took fifth place in a second entry for Ganassi. Dixon shared the wheel with Alex Lloyd and 2007 IndyCar champ Dario Franchitti. The team finished four laps behind.

Three-time defending Sprint Cup champion Jimmie Johnson and his Bob Stallings Racing teammates overcame early mechanical problems to finish seventh. Johnson joined Alex Gurney, Jon Fogarty and 1996 Champ Car champion Jimmy Vassar in the effort.

Childress-Howard Motorsports, co-owned by NASCAR team owner Richard Childress, also suffered mechanical problems with their Pontiac Crawford in the early- going, but Sprint Cup regular Casey Mears, IndyCar veteran Danica Patrick, three-time Rolex 24 winner Andy Wallace and Rob Finlay managed to give the team an eighth-place finish.

Other notable drivers participating in this year's event included: AJ Allmendinger, Colin Braun, Max Papis, Kyle Petty and Boris Said.

The Donohues became the first father-son winners in the history of the event, three days after the pair joined Dan and Alex Gurney as the races lone father-son pole winners.