Tony Stewart :chair: won for the fifth time in seven races with a dominant performance Sunday at Watkins Glen International that padded his lead in the Nextel Cup standings.

But there was an anxious moment at the end after a late caution forced two extra laps.

Stewart radioed in that he had an alternator problem, forcing him to shut off some systems and switch to a backup battery. Still, he drove away from Robby Gordon on the restart and was in no danger of being caught.

Stewart stopped at the flagstand, took the checker and drove around the track to the cheers of the crowd. But he didn't climb the catch fencing as he had after his three most recent wins.

The 24th victory of the Indiana driver's career came a week after he won for the first time at Indianapolis Motor Speedway. The first-place finish here gave Stewart a 105-point lead over Jimmie Johnson, who finished fifth.

Stewart won the $4.6 million Sirius Satellite Radio at The Glen for the second year in a row. It was the fifth road-course win for Stewart in five years. He won in June on the only other NASCAR road course -- the serpentine layout in Sonoma, Calif.

It was his third career win on this 2.45-mile track known as New York's Thunder Road. He started on the pole because rain Saturday prevented the completion of qualifying and forced NASCAR to set most of the 43-car field on car-owner points. Stewart was easily the fastest driver of those who took qualifying laps before the rain came.

In the race, his Chevrolet led 83 of 92 laps and beat the Chevy of Robby Gordon by 1.927 seconds on the 11-turn track that snakes through the hills south of Seneca Lake.

Stewart is virtually assured of being no worse than third when NASCAR resets the standings at five-point intervals for the top-10 drivers after four more races. Then the 10-race Chase for the Championship begins Sept. 18 at New Hampshire International Speedway, where the 2002 Cup series champion won last month.

He and Greg Biffle share the series lead with five wins apiece.

Road-racing specialist Boris Said finished third Sunday in a Chevy, followed by the Dodge of road racer Scott Pruett and Johnson's Chevy.

The winner averaged 86.804 mph in a race slowed seven times by 14 caution laps. There were nine lead changes among seven drivers.

Rusty Wallace was sixth, followed by Mark Martin. Brian Vickers, Joe Nemechek and Dale Earnhardt Jr. completed the top 10.

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