LONG POND, Pa. - Kurt Busch made it a clean sweep for Roush Racing at Pocono.

With veterans Rusty Wallace and Mark Martin trying desperately for one last shot at glory on the mountaintop, Busch spoiled the going away party and kept moving toward another Nextel Cup title.

Busch dominated each end of the Pennsylvania 500 on Sunday and raced to his second win of the season, joining teammate Carl Edwards as winners for owner Jack Roush this year at Pocono Raceway.

"This is Pocono perfection for Jack this year and for us to dominate today, it's just a tribute to what the crew is doing for me - and that's building great race cars," said Busch, who earned his 13th career victory.

Busch is also building a case for a second straight NASCAR Nextel Cup championship. He remained steady in fifth place in the points race, 262 behind leader Jimmie Johnson.

With only six races left to determine who qualifies for the "Chase for the Cup," there's little room for error. Dale Jarrett holds the 10th - and probably final - spot over Jamie McMurray (nine points back) and Carl Edwards (12 points behind).

The "Chase for the Cup" begins at New Hampshire International Speedway on Sept. 18.

"I got out of the car and said, 'I think I can still do this,'" Wallace said.

Wallace, a four-time winner at Pocono who is retiring, was second in his final race at the 2.5-mile triangle track. Perhaps driving his last race at Pocono, Martin finished third in the No. 6 Ford. Carl Edwards followed his win here in June with a fourth-place finish.

While Wallace is firm in his commitment to retire, Martin may have his farewell tour extended another year because Roush is without a driver for the No. 6 Ford next year.

"I still have my decision," Martin said. "I don't even like talking about it because I want to go truck racing next year."

Busch led 131 of the 203 laps, with the race extended three laps and ending on the green-white checkered flag because of four cautions that came out after he took the lead for good on the 183rd lap.

Busch started second in his No. 97 Ford and had the strongest car from the beginning, taking the lead from polestitter McMurray on the first turn of the first lap. He led most of the first half of the race until a slow pit stop with 90 laps remaining slowed him down.

That allowed some of NASCAR's old dogs to make a run. It didn't shake Busch's confidence, however.

"It was just a matter of time. I thought we could do it," he said.

Martin led 26 laps and Wallace led 18 until he was caught by Busch coming out of turn three.

"To be able to race veterans like Rusty Wallace and Mark Martin, who are in their final years, it was exciting for me," Busch said.

The win also capped a big day for Roush Racing which had three of the top-four finishers - Busch, Martin and Edwards. Roush had competed in 34 races at Pocono since 1988 without a win before the two victories this year.

"Predictably, Kurt was going to be out front, down and gone, but I was real nervous how the rest of it was going to work out," Roush said.

The result was particularly impressive for Edwards, who was forced to start at the back of the field because he skipped qualifying to compete in Saturday's Busch Series race. Somehow, he made it near the front of the pack - just not far enough.

Johnson maintained his overall points lead with a 12th place finish. Tony Stewart moved to second in the standings with a seventh-place finish, Greg Biffle (17th) is third followed by Wallace.

Jeff Gordon finished 13th and Dale Earnhardt Jr. was two laps off the leader in 32nd place as two of NASCAR's most successful drivers are running out of time to crack the top 10.

"A lot of things happened that nobody really knows about, but we got the car better at the end," Earnhardt said.

Busch, who also won this year at Phoenix, had his seventh top-five finish and successfully navigated a Pocono track that was sharply criticized by drivers this weekend.

NASCAR had the track patched near the treacherous tunnel turn before the race after it was damaged in Saturday's ARCA stock-car race. The track's reputation already took a hit after June's race when drivers were victimized by blown or cut tires.

While some drivers said it was mostly the result of overaggressive driving, NASCAR tried another approach by installing a curb inside turn two.

There were no major problems on Sunday. The track was still bumpy, but Busch made it look smooth.

"A few more small races before we get into the chase and then it's time to go," he said.