A.J. Allmendinger had tried to win the Rolex 24 At Daytona for six years. In fact, he hadn't won a race anywhere for five years.

His friend and Grand-Am Rolex Series car owner Michael Shank -- whom Allmendinger thinks so much of he'll be Shank's partner in an IndyCar Series program this season -- had eight previous Rolex 24 attempts that were steeped purely in frustration.

So their victory Sunday in the 50th anniversary of Daytona International Speedway's season-opening event provided enormously equal parts relief and satisfaction -- even if it has nothing to do with Allmendinger's full-time job, racing Cup Series stock cars for legendary owner Roger Penske.

"I'm going to cherish this," Allmendinger said in a moment of reflection. "It's such a prestigious race. It's one of those races you want on your resume and you want to say that you were part of a victory."

Shank was stoutly in Allmendinger's camp even though he'd made a deal with his buddy. If they won the race, Shank said he would shave Allmendinger's personal flame-tinged "AJ" logo into the side of his head. In the post-race media briefing, their affinity was obvious.

"I'll be doing [that] this week," Shank said of his promise. "I'll tell you what [Allmendinger] calls me. He calls me Shankapotamus. I guarantee you, Roger [Penske] won't get anything shaved in the side of his head, I'm pretty sure. That's why [Allmendinger] likes me better."

That was just one of several mirthful post-race moments for Shank's two-team ensemble. For the previous 24 hours they were all business, and Allmendinger was chairman of the board, leading 69 of the race's final 90 laps, and 90 in total.

Allmendinger put an exclamation point on his seventh consecutive attempt with Shank, the former open-wheel driver turned team owner, by driving the final 167 minutes in a car that included Shank's full-season sports car ace, Ozz Negri and his teammate, John Pew along with IndyCar Series regular Justin Wilson. Negri led 67 laps and Wilson, 92.

The victory capped a month in which Allmendinger was named the driver of Penske's No. 22 Dodge in the Sprint Cup Series, a car that's qualified for the Chase in five of eight seasons. Allmendinger initially laughed, but quickly got serious when he was asked about his recent history.

"It's always cool to be me," said Allmendinger, who burst from his No. 60 Ford Riley in Victory Lane waving an American flag. "No, I'm just kidding. The last five years it's actually sucked to be me."

That included a precursor when he won five of the final nine races in the 2006 Champ Car World Series before making an ill-fated jump to the startup Cup Series Red Bull Racing Team in 2007. Allmendinger missed 22 of the first 39 Cup races he attempted.

"2007 was hell, honestly -- the worst year of my life when it came to my career," Allmendinger said. "There was plenty of times in my bus on Friday missing a race that it was either, 'should I go back to IndyCar or slit my wrists,' honestly. It sounds kind of over the top, but I knew I wanted to be in the Sprint Cup Series. That's where the best of the best was."

Four years later, Allmendinger's arrived, and the Rolex win was significant icing on his cake. He credited Shank for a considerable part of it.

"It's been a tough time," Allmendinger said. "But the fun thing was a guy like Mike Shank, no matter how I felt about myself after a tough year or tough season, he never wavered on whether he wanted me in the car. Every year we said we were doing this.

"That's why I love this guy so much. He's always been there for me. I would do anything for him, and I'm just happy that I can be a small part of this victory for him, and it's really cool not only to win the race but to have two cars on the podium."

Shank's team car, which included Allmendinger's fellow Sprint Cup driver Michael McDowell on its roster, finished third, sandwiching Starworks Motorsports' pole-winning Ford Riley. The two NASCAR men were able to reflect on racing in multiple series.

"As Michael McDowell said, I think Sprint Cup racing is the toughest in the world right now," Allmendinger said. "I mean, it's so hard to win. You know, I look at this year as my best opportunity to go win a Cup race. But that's easier said than done.

"Right now I'm just going to take this for what it's worth, not think about anything for a couple days, and just enjoy it. Right now it's the biggest win I've ever had because we've worked for seven years to get to this point with Mike Shank, and we've been so close so many times. It's funny, the last three hours when I got in the car, it was just like, 'OK, we've been here before, and something has happened to take us out.' "

It didn't happen this time. Allmendinger was virtually flawless.

After 23-and-a-half hours of racing, Allmendinger, who earlier in his stint had swapped paint with sports-car stalwart Allan McNish while battling for the lead -- which he swapped nine times in his final 92-lap stretch -- turned the fastest laps on the track more often than not as he maintained an advantage on Ryan Dalziel that varied from more than 11 seconds to 5.198 seconds at the checkers.

"Honestly, that's probably the most fun three hours of racing that I've ever had," Allmendinger said. "Part of it is because we won, so if we would have lost it would have sucked. I knew those last three hours I was going to go flat out because the [Starworks] car, the [defending champion] No. 01 at that point were really fast.

Allmendinger said he's ready to get taken down a peg when Daytona reopens in two-and-a-half weeks for Speedweeks. But until then he's going to enjoy what he called "the biggest win for me that I've ever been a part of."

"They'll knock me back down when I get to Speedweeks, don't worry about that -- when I get to the Cup garage and they remind me I haven't won again," Allmendinger said, before mentioning there was one important element winning the Rolex did bring -- in addition to a very pricey Rolex wristwatch. "It's not what I learned or technique, it's just confidence.

"You win a race, especially as big as the 50th anniversary of the Rolex, it's just confidence. And that'll take a race-car driver or anybody for that matter in any career further than he can expect."

The event was also a huge success for Roush Yates Engines, which will try to defend its Daytona 500 victory with Trevor Bayne in four weeks. RYE built the powerplants for the top-three cars.

This Rolex 24 was a disappointment for former 24-hour winner Juan Montoya, his Earnhardt Ganassi Racing Sprint Cup teammate Jamie McMurray and Chip Ganassi Racing, the event's defending champion and winner four of the past seven years -- twice with Montoya.

The car shared by Montoya, McMurray and Ganassi's IndyCar champions Dario Franchitti and Scott Dixon suffered a broken shifter in the middle of the night and never recovered, finishing fourth, a lap down. Ganassi's defending champion car, led by Scott Pruett, led 96 laps in the first 22 hours but had to replace a gear stack and fell to sixth, four laps behind.

Andy Lally, the 2011 Cup Series rookie of the year, scored his second consecutive GT class victory and his third in the past four years, but with a twist. Lally won the 2011 Rolex 24 and ran most of the Sprint Cup season for TRG Motorsports owner Kevin Buckler. But "philosophical differences" led the longtime partners to split near the end of the season. Lally prevailed in the rookie of the year race despite skipping the NASCAR season finale and joined TRG's rival Magnus Racing for the 2012 Rolex Series season.

On Sunday, Lally and his three teammates' Porsche GT3 Cup beat TRG's lead Porsche by 9.412 seconds, a result Lally called "absolutely epic."