Jimmie Johnson pulled off a clean sweep at Pocono Raceway in Long Pond, Pa., yesterday.

Johnson dominated at the track for the second time in seven weeks, building on his NASCAR Nextel Cup points lead and winning the Pennsylvania 500 in a race that further shuffled the standings.

"That racecar was incredible," said Johnson, who is the first driver to win the Pocono 500 and Pennsylvania 500 in the same year since Bobby Labonte in 1999.

Under the old points system, Johnson probably could have cruised toward his first career points title. Instead, he'll be lumped with the rest of the drivers in the top 10, along with any others within 400 points of the lead after the 26th race, to compete for the championship over the last 10 races of the season.

The "Chase for the Cup" begins at New Hampshire International Speedway on Sept. 19.

Mark Martin continued a recent string of solid finishes by placing second, and Kasey Kahne was third. Greg Biffle and Jeff Gordon rounded out the top five.

"I don't know if anyone can beat Jimmie Johnson here right now," said Gordon, who moved to second in the standings.

While Johnson cruised, some of the big names in the top 10 struggled. Tony Stewart, Kevin Harvick, Bobby Labonte and Kurt Busch all failed to finish while Ryan Newman was 13th.

Harvick fell from ninth overall to 10th after failing to finish a race for the first time since October 2002 in Atlanta. Labonte dropped from seventh to ninth overall, while Newman jumped from 10th to eighth.

Jeremy Mayfield, Kahne and Martin all got closer to that 10th and final spot.

"That fact is a miracle," Martin said. "Now can we make it to the top 10? We all need to go win the Brickyard. That would make up for all the heartbreak we experienced this year."

Dale Earnhardt Jr., with second-degree burns on his legs, neck and chin from a crash two weeks ago during a sports car event, started the race to get the championship points but yielded the seat after completing 52 laps to John Andretti.

Andretti made another quick pit stop to readjust, but finished 25th after the car was black-flagged by NASCAR for not maintaining the minimum speed.

"I could have run the rest of the way, but the car was so bad, there was no use in me being in there wasting my time," Earnhardt said. "I should be out of the car trying to get better."

Earnhardt said he would be ready for this week's Brickyard 400, perhaps the marquee event aside from Daytona on the NASCAR schedule.

Stewart was knocked out when he wrecked on Lap 108. Sandwiched between Kahne and Kyle Busch, Stewart's No. 20 Chevrolet got loose and the nose slammed the wall. The car rolled backward -- just narrowly avoiding a rush of cars -- and came to rest in the infield.

Stewart looked angry and had his hands on his hips as he looked at his mangled car back in the garage area, but NASCAR's reigning bad boy kept his cool.

* IRL: Rookie P.J. Chesson earned his first Indy Racing League Infiniti Pro Series victory at Michigan International Speedway in Brooklyn, Mich.

Chesson held off series leader Thiago Medeiros to win the Paramount Health Insurance 100 with an average speed of 173.112 mph.

Medeiros finished second, 0.0941 of a second behind, and Al Unser was third.

Chesson and Medeiros swapped the lead for most of the race, and ran apart from most of the 10-car field for the last several laps on the two-mile, D-shaped oval. . . .

Buddy Rice won a last-lap showdown with Tony Kanaan, taking the Michigan Indy 400 by .0796 of a second for his third IRL victory of the season.

Rice's average speed -- 182.123 mph -- was the fourth-fastest in IRL history.

Dale Earnhardt Jr., still recovering from burns suffered two weeks ago, exits early from Pennsylvania 500 after earning championship points.