DAYTONA BEACH, Fla. — The rain finally fell on Daytona, then it took another 20 minutes for the real downpour.

Matt Kenseth, the quiet, unassuming former NASCAR champion who had never been in contention at the Daytona 500, cried as he celebrated the biggest victory of his career in yesterday's rain-shortened running of The Great American Race.

It was an unexpected show of emotion for one of NASCAR's most underappreciated stars.

Then again, he'd waited a decade for a legitimate shot at the Super Bowl of stock cars. And the failures and frustrations of late had started to wear on the 2003 series champion, who vented to his wife just the day before the 500.

"I was telling her, 'Man, I'm really getting fed up with not winning, with not being a contender,' " he said. "It was actually starting to weigh on me more than we thought."

Rain hung over Daytona International Speedway all day yesterday, turning the season-opening event into a race against Mother Nature.

Elliott Sadler prayed for the sky to open up when he was out front, but he was answered a tick too late. Kenseth used a huge push from Kevin Harvick to slide past Sadler 54 laps from the finish, and mere seconds before Aric Almirola spun to bring out a caution.

That's when the rain began, and after two caution laps, NASCAR sent the drivers to pit road to wait out the storm. Most drivers climbed from their cars to await NASCAR's decision, but Kenseth stayed put through the delay.

"I actually am a pretty emotional guy. You guys just don't always really see it," he said. "I just wanted to wait until it was either over or we were going to go race again. I didn't want to let my emotions get too high one way or another."

The race was called after 152 of 200 laps. It was just the fourth rain-shortened 500 in the race's 51-year history, and first since Michael Waltrip's 2003 win.

No one will blame Kenseth if he worries next year NASCAR will allow rain tires and windshield wipers. After all, NASCAR overhauled its championship-deciding system a month after Kenseth's bland 2003 title run.

"Man, I'm going to go paint the town plaid," he deadpanned to a columnist who in 2003 wrote Kenseth has no personality.

Coming off one of the worst seasons of his career, Kenseth's 2009 start seemed to be headed in the wrong direction, too. He wrecked his primary car, had to go to a backup and started at the back yesterday.

Had rain not been forecast, he might still have been running at the back of the field with 54 laps to go, because that's where veterans usually wait out the dicey Daytona racing before making a late charge.

But the weather radar showed the rain was coming, and crew chiefs up and down pit road urged their drivers to go for it.

Kenseth sliced his way through the field, then used the push from Harvick to take the lead away from Sadler.

"If I would have made a better and smarter move, I'd be in Victory Lane right now," Sadler bemoaned. "Very hard to swallow. Very emotional."

The win was the first for Kenseth since the 2007 season finale, a streak of 36-winless races. He was also 11th in the final season standings, his lowest since he was 13th during a winless 2001 campaign.

But he's on top again, and gave owner Jack Roush his first Daytona 500 win in the process.

"I tell you what, after last year, winning a race means a lot to me," Kenseth said. "I've had a lot of great opportunities in my life — from my family getting me in racing and really ... all the sponsors that we have that have stuck by us and made this happen in an up-and-down economy.

"Man, I don't know. Winning the Daytona 500 is definitely a dream moment. It's just an unbelievable feeling."

Harvick, who used a push from Kenseth to win the 500 in 2007, finished second and said Kenseth would be a popular winner among his competitors.

"I think Matt's obviously a pretty standup person and a great race car driver," Harvick said. "I think he's one of those guys that he can win seven or eight races in a year and never receive any credit. He's a really good race car driver."

AJ Allmendinger, who had to race his way into the field in one of Thursday's qualifiers, finished third.

Clint Bowyer was fourth, and Sadler was fifth, devastated he lost the lead moments before the rain stopped the race. He led 24 laps and was out front during an earlier caution, hoping the sky would open up at that moment to give him the win.

"That's just my luck," he radioed his crew. "It's raining on the radar and not on the track. Welcome to the team."