HOMESTEAD, Fla. -- Brad Keselowski, loud, a little buzzed and soaked in beer, bounded through the door with an oversized bottle of champagne in one hand and his cellphone in the other. He plopped down next to Roger Penske, a pillar of the American auto industry, and triumphantly slapped him on the back.

"We did it boss," Keselowski hailed.

"Did you bring your tweeter?" the 75-year-old Penske replied.

NASCAR's oddest couple captured its biggest prize Sunday night, when Keselowski brought Penske his first Sprint Cup championship 40 years after the owner's first stock car race. He beat five-time champion Jimmie Johnson of mighty Hendrick Motorsports while delivering the crown that fills a glaring hole on Penske's otherwise sterling racing resume.

Penske is considered the gold standard of open-wheel racing -- he has 15 Indianapolis 500 wins -- and his empire makes him one of the most successful businessmen in America. But until Sunday night at Homestead-Miami Speedway, his NASCAR program was never more than average.

But the program really turned behind Keselowski, you know, the kid you first heard about when he tweeted from inside his car during the season-opening Daytona 500 earlier this year. So it was fitting that his first act as champion was sending a tweet, of course, from inside his car. "We did it," he posted with a picture.

Then the party really began.

The blue collar, Twitter-loving, Michigan native chugged sponsor Miller Lite's product, donned goggles to douse the Blue Deuce crew with champagne, and imagined how his life will change as NASCAR's champion. At 28, he's the eighth youngest champion in NASCAR history and proud he doesn't have a date for the Nov. 30 champions banquet in Las Vegas.

Keselowski might not have seemed like Penske material three years ago, but he's a cornerstone now.

He was a developmental driver for Hendrick Motorsports in 2008 when he went to see Penske, convinced he could be the driver to bring "The Captain" a coveted Cup championship. He wiggled free from his contract a year later, and had a second-tier Nationwide championship -- and a closet full of starched white Penske shirts -- to show for his convictions.

Now, three years into the partnership, he and Penske have that Cup championship and a connection no one saw coming.

Keselowski needed 125 starts to win his first championship, the fewest starts since four-time champion Jeff Gordon won his first title in 93 starts in 1995. Keselowski also won a second-tier Nationwide title in 2010, his first season with Penske and the owner's first official NASCAR championship.

Gordon, who avoided suspension this week but was fined $100,000 by NASCAR for intentionally wrecking Clint Bowyer last week at Phoenix, overcame the controversy to win the race in a 20th anniversary celebration for sponsor Dupont and Hendrick Motorsports.

It was Gordon's first victory at Homestead, which leaves Kentucky as the only active NASCAR track where he's yet to win.

Who did Gordon beat? Bowyer, of course.

And Bowyer's second-place finish moved him to a career-best second in the final standings. Third-place went to Ryan Newman, who got his break in NASCAR with Penske and spent seven seasons driving for the owner.

Keselowski started the race up 20 points on Johnson, who blew a tire and crashed last week at Phoenix to give Keselowski a nice cushion. He needed to finish 15th or higher in the finale to wrap up his first championship. But the Penske team took nothing for granted -- not after Will Power crashed in the IndyCar finale to blow a 17-point lead and lose the championship.

And this one got tight, too, especially when Keselowski ran out of gas on pit road during green flag pit stops. It put him a lap down with Johnson leading, and Keselowski and crew chief Paul Wolfe frantically tried to figure out how dire the situation had become.

Wolfe crunched the numbers, figuring the No. 2 Dodge would cycle out in the mid-20s, a lap down from the leaders.

But minutes later, Johnson went to pit road for his own stop and pulled away with a missing lug nut. NASCAR flagged the Hendrick Motorsports team and Johnson was forced back to pit road for another stop.

It got worse for Johnson from there. He broke a rear end gear in his Chevrolet and went to the garage with 40 laps to go, essentially clinching the championship for Keselowski.

No longer needing to save fuel, and no longer needing to play it conservatively, he waived off Wolfe's playbook.

That's been Keselowski's attitude since he burst onto the NASCAR scene. He first caught attention as a brash driver for Dale Earnhardt Jr.'s Nationwide Series team, and he was unapologetic for his aggressive driving and his refusal to back down in long-running feuds with established stars Denny Hamlin and Carl Edwards.

But he's been calmer and focused since joining Penske in 2009. Still, his fame had been largely for the Daytona 500 tweeting.

NASCAR loved the attention it received, but quietly admonished him later for having a phone in his car, which is banned because it can manipulate electronic fuel injection systems. So when he tweeted again last week under red at Phoenix, NASCAR fined him $25,000 -- which angered fans who felt a mixed message had been sent.

But Keselowski, who was tweeting into the early morning hours Sunday, handed his phone over with no resistance right before he climbed into the car at Homestead.

The win is the first for Dodge since Richard Petty's Cup title in 1975, and comes as the manufacturer is leaving NASCAR. Penske announced days after the Daytona 500 it will move to Ford next year, and it led to Dodge's decision to pull out of NASCAR.

Copyright 2012 by The Associated Press. All rights reserved. Material may not be redistributed.

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