WATKINS GLEN, N.Y. -- Kyle Busch won the Centurion Boats at The Glen on Sunday and became the first driver in NASCAR history to win three road course races in one season.

After rivals said they thought he was slipping following two straight lackluster races, Busch led for 52 laps from the pole at Watkins Glen International.

``That kid's awesome,'' said Steve Addington, Busch's crew chief. ``I can't believe we don't win a race in three or four weeks and we're in a slump.''

Busch, who also clinched a spot in the 10-race Chase for the Sprint Cup title, has won 16 races in NASCAR's top three series this season -- eight in Sprint Cup, six in Nationwide and two in trucks -- and three came on road courses. He won the Nationwide race in Mexico in April and the Cup race at Sonoma in June before finishing second here on Saturday in the Nationwide race.

No driver in NASCAR history had won three road races in one season, and only Jeff Gordon, Stewart and Robby Gordon had swept both Cup road events in the same year.

The victory also gave Busch 80 bonus points for the Chase, 50 more than Carl Edwards, who moved into second in the overall standings after finishing ninth.

After a 43-minute red-flag stoppage due to a multicar pileup with eight laps to go, Busch held off Joe Gibbs Racing teammate Tony Stewart, who was bidding for his fifth win here in eight starts. It was the second straight runner-up finish for Stewart.

Marcos Ambrose of Australia, who started last in the No. 21 Wood Brothers Ford, finished third a day after winning the Nationwide race. He was followed by Juan Pablo Montoya and Martin Truex Jr.

Kevin Harvick was sixth, followed by Jimmie Johnson, Denny Hamlin, Edwards and Kurt Busch. Matt Kenseth finished 12th to move into 12th place in the standings, 22 points ahead of Clint Bowyer in the race for the final slot to make the postseason.

Jeff Gordon, a four-time winner at Watkins Glen, began the day sixth in points, but faded quickly after a strong start and finished 29th. He retained his place in the standings.

Dale Earnhardt Jr., who has never won a Cup race on a road course, took off to a big lead after passing Busch on the second lap and looked like being a strong contender. But poor pit strategy derailed his effort and he finished 22nd after leading 33 laps and fell two slots in the standings to fourth.

Running up front most of the day around the 2.45-mile (3.9-kilometer), 11-turn course, Busch allowed Stewart to pass him on lap 54 so Stewart could collect five bonus points for leading, then quickly regained the top spot when Stewart moved over the next time around.

Busch and Stewart made their final pit stop one lap later and regained the top two spots on lap 65 when Earnhardt gave up the lead and pitted under caution, losing all of his track position.

The JGR teammates stayed 1-2 until Ryan Newman, running third and hoping for a strong finish to enhance his chances of making the Chase, slid off course in turn 1 on lap 79, bringing out the third caution of the race and bunching the field for a nine-lap dash to the finish.

The dash was shortlived. A stunning multicar crash on the final turn of lap 82 of the 220.5-mile (355-kilometer) race brought out a red flag stoppage that lasted 43 minutes.

The pileup started when Michael McDowell spun David Gilliland, who caromed off the wall and was slammed hard again by Bobby Labonte, with both cars spinning violently around. Max Papis, Dave Blaney, and Sam Hornish Jr. also were unable to avoid the carnage, with Hornish slamming hard into the water barrier at the entrance to pit road.

Labonte was taken to a local hospital for evaluation, but the rest of the drivers were taken to the care center and released.

The race resumed with six laps remaining, and Busch sailed away on the restart and was never challenged.