Montoya and his Chip Ganassi Racing teammates went into the 47th Rolex 24 going for an unprecedented fourth straight victory for their car owner, but it was David Donohue and the long-suffering Brumos Porsche team that came out on top.
Donohue was at the wheel of the winning car in the last hour Sunday, chasing down and passing NASCAR star Montoya just 41 minutes from the finish, then holding the former IndyCar and Formula One driver off by the closest margin in race history.
The victory came on the 40th anniversary of a victory by Donohue's late father at Daytona International Speedway.
It was the biggest win of his career for Donohue, who started from the pole in the team's Porsche Riley on Saturday afternoon. He combined with former Indianapolis 500 winner Buddy Rice, Antonio Garcia and Darren Law to win.
"We ran hard the whole time" said Donohue, son of Indy 500 winner Mark Donohue, who died in 1975 after a crash during a Formula One test. The son was just 8 years old at the time.
"It's a good story line but, to be perfectly honest, he's been gone for quite some time and our guys have done the hard work and putting in the effort to win this race," Donohue added. "I'm certainly really very proud of my father and his accomplishments and what he's done, and just coincidentally we happened to nail it on the 40th anniversary of his win.
"But I feel more of an attachment to the effort my guys have put in and Brumos. ... That's where my heart is, to be honest."
Four Daytona Prototypes, including the third-place sister Brumos Porsche -- co-driven by six-time Daytona winner Hurley Haywood, J.C. France, son of NASCAR board member Jim France, Terry Borcheller and Joao Barbosa -- finished on the lead lap in an event that had only once before had two cars on the lead lap.
The Ganassi drivers insisted that the Porsches had a big advantage on power, particularly on the portion of the 3.56-mile road circuit that encompasses about three-fourths of the 21/2-mile NASCAR oval.
"I said before the race that if the Porsches don't have any problems they're going to beat us," said Montoya, who had combined with teammates Scott Pruett and Memo Rojas to win his first two Rolex 24s. "Every stint, apart from the last one, they drove away from us. We did what we could. I gave it 110 percent."
Donohue and his teammates pooh-poohed the supposed power advantage.
"There's no doubt we had good top end, but you really had to know how to use it," Donohue said, crediting former NASCAR driver and IROC test driver Dave Marcis with teaching him the art of passing on Daytona's high banks. "I've done a lot of testing here with the IROC guys.
"It's different cars, but the principles still apply. That's how I was able to do it, to be honest with you. I couldn't just sit there and drive by. You really had to plan it."
Law called the Ganassi team's gripes sour grapes, noting, "They crossed the line 50 feet behind us and it was a fight the whole way through."
The winners completed 735 laps, a total of 2,616.6 miles.
Montoya replaced teammate Pruett in the cockpit of the Ganassi Lexus Riley with about 21/2 hours left and appeared to be in control after he took the lead during the 23rd hour.
A record 25 full-course cautions kept things close and the final yellow of the grueling race came out for debris with just over one hour to go. All four of the lead-lap cars took the opportunity to make their final pit stops.
Donohue replaced Garcia in the driver's seat of the No. 58 car during the stop and somehow managed to stay right behind Montoya as they left the pits.
When the green flag waved with 53 minutes to go, Donohue went after the more experienced Montoya, nearly passing him several times over a period of several laps. They nearly bumped at least once before Donohue finally took advantage of slower GT class traffic to slip past the Lexus into the lead on lap 710.
"It was just a matter of getting into some traffic at some point," Montoya said. "I was actually surprised to stay with them. I drove my butt off to see if they would make a mistake. They made a couple of mistakes, but their car was so comfortable for them there was nothing we could do."
Montoya chased Donohue to the finish but wound up 0.167-seconds behind, a record, and only about four car lengths back. The fourth-place Ford Dallara of Wayne Taylor, Max Angelelli, Pedro Lamy and Brad Friselle was 7.589 seconds off the pace and in sight of the winners.
The previous closest 1-2 finish was 30.879 seconds in 2000 when a Dodge Viper held off a Chevrolet Corvette.
The second Ganassi entry, co-driven by IndyCar stars Scott Dixon and Dario Franchitti -- the fourth member of last year's winning team -- and Alex Lloyd, had problems in the early morning hours Sunday and wound up fifth, four laps behind the winners.
Roger Penske, who owned the car in which Mark Donohue won the 1969 race, was back at Daytona and racing in the Grand-Am Rolex Series with a new Porsche Riley after winning the last two championships in the rival American Le Mans Series. The trio of Timo Bernhard, Romain Dumas and Ryan Briscoe led several times in the early going, but fell to sixth and finished 18 laps off the pace after having to replace a broken rear end Sunday morning.
Jimmie Johnson, the three-time reigning NASCAR Sprint Cup champion whose team finished second here a year ago, had some bad luck early in the Pontiac Riley he shares with former CART champion Jimmy Vasser, Alex Gurney and Jon Fogarty. Johnson stopped Saturday night to have a broken tail light replaced and wound up having the gearbox replaced after he broke the transmission trying to get the car in gear. The team wound up seventh, 21 laps behind.
Ganassi team takes aim at another Rolex win
Four-way battle at Daytona with 5 hours to go