Dale Earnhardt Jr. pulled away from Jeff Gordon in a pair of overtime laps yesterday to win the NASCAR Nextel Cup Checker Auto Parts 500 at Phoenix International Raceway in Avondale, Ariz., tightening up the championship chase with two races to go.

Kurt Busch finished 10th and held on to the series lead. But the top four drivers are separated by just 48 points heading into next Sunday's event in Darlington, S.C.

Earnhardt was in third place, trailing Gordon and Casey Mears, when a caution came on Lap 292 of the race scheduled to go 312. Last Sunday in Atlanta, Earnhardt had a top-five finish all but wrapped up when he collided with rookie Carl Edwards, wound up 33rd and lost precious ground in the 10-race championship.

This time, Earnhardt stayed out and wound up passing Mears for second place on Lap 298, moments before another caution came out for Jamie McMurray's wreck.

On the restart on Lap 303, Earnhardt swung his No. 8 Chevrolet to the inside of Gordon's car, pulled alongside and then shot into the lead. He began to pull away when Mears, with a tire going flat, spun into the wall, bringing out yet another yellow flag on Lap 307.

Moments later, Robby Gordon's engine blew. NASCAR stopped the cars on track on Lap 310 as safety workers cleaned up the debris from Mears's crash and the oil from Gordon's engine failure.

Once the race resumed, NASCAR ordered one extra lap of caution, then finished with only the second green-white-checker overtime since the rule was adopted earlier this year.

Earnhardt pulled away once the green flag waved for his sixth win of the season. Ryan Newman, who started from the pole, finished second, followed by Jeff Gordon, Kevin Harvick, Kasey Kahne, Jimmie Johnson, Rusty Wallace, Tony Stewart and Bobby Labonte.

Busch leads by 41 points over Jeff Gordon, 47 over Earnhardt and 48 over Johnson.

* CHAMP CAR: In Mexico City, Sebastien Bourdais took his first series title, beating teammate Bruno Junqueira with a flag-to-flag victory in the Mexican Grand Prix.

Frenchman Bourdais managed to win despite a slide on Lap 42 that cost him about 12 seconds of the lead he held over Newman/Haas teammate Junqueira. The Brazilian finished second in the standings for the third year in a row.