Jimmie Johnson finally closed the deal -- the hard way.

After having the Nextel Cup elude his grasp for four consecutive years, Johnson won stock car racing's biggest title Sunday -- and its $6.2-million prize -- by overcoming two early setbacks and finishing ninth at Homestead-Miami Speedway.

The El Cajon, Calif., native needed to finish only 12th or better in the Ford 400 to win his first championship. He started with a 63-point lead over Matt Kenseth in the final event of NASCAR's 10-race Chase for the Cup and the 36-race season.

"This is just the most amazing day of my life," an emotional Johnson, 31, said after hoisting the Nextel Cup in front of the main grandstands.

It also was an emotional day for Greg Biffle, who won the Homestead race for the third straight year in a Roush Racing Ford after learning this month that his father was ill.

The victory was a positive end to an otherwise forgettable year for Biffle, a Kenseth teammate who had only one previous victory this year and failed to qualify for the 10-driver Chase.

"Congratulations to Jimmie Johnson," said Biffle, runner-up in the Chase last year to Tony Stewart. "Hopefully we'll be in that position next year."

Martin Truex Jr. was second, the best finish in his first full year in the Cup series for the Dale Earnhardt Inc. team.

After Johnson took the checkered flag and slowed for his cool-down lap, his teammate Jeff Gordon and some other drivers affectionately bumped the side of his No. 48 Lowe's Chevrolet in congratulations.

With the Cup now safely in hand, Johnson said he felt the growing pressure as race day neared.

"It started building up over the last couple of weeks," Johnson said. "You get so caught up in worrying about things you can't control."

But, he said, "I felt good when I got in the race car, and was calm and at peace."

It was the sixth championship for Johnson's team owner, Rick Hendrick, who won four with Gordon and one with Terry Labonte.

"This one feels especially good, because of how close [to the title] Chad and Jimmie have been the last couple of years," Hendrick said.

Besides Kenseth, the only other Chase drivers who had mathematical chances to win the Cup were Kevin Harvick and rookie Denny Hamlin, who were 90 points behind, and Dale Earnhardt Jr., who was 115 points behind.

Hamlin, Harvick and Kenseth ran solid, if fruitless, races Sunday and all finished in the top 10.

Earnhardt was the class of the field midway through the race, which started on a clear, breezy late afternoon. But as night fell and the race progressed under the lights, Earnhardt's car faded. He also skimmed the wall and finished 19th.

The result: Kenseth finished second in the Chase, 56 points behind Johnson, followed by Hamlin, Harvick and Earnhardt.

"I'm happy to finish second to Jimmie," Kenseth said. "It's been a great season."