Stewart conserved enough fuel and easily held off Marcos Ambrose in the closing laps to become the road course king at the 2.45-mile track.

"This is my house right here," Stewart said after taking his first road course event as a driver and owner in the Sprint Cup Series. "We've run really well here the last eight years."

Stewart has finished either first or second in the last six races at Watkins Glen. "Smoke" also recorded his third victory of the season and the 36th of his Cup career.

"We weren't good enough at the beginning to win, but we needed to make some changes to get better," he said. "The pit crew did an awesome job to put the car back to where it needed to be."

Thundershowers at Watkins Glen on Sunday forced NASCAR officials to postpone the 90-lap race one day. For the second straight week, a Sprint Cup race ran on a Monday. Bad weather at Pocono last week also caused a one-day delay.

Ambrose finished second, his career-best in the series. Ambrose won the Nationwide event on Saturday at Watkins Glen.

"I had to work really hard to keep up with 'Smoke," Ambrose said. "I was closing in, but he just didn't make a mistake."

Carl Edwards came in third, while Kyle Busch, last year's winner at Watkins Glen, came in fourth.

"That wore me out right there," Busch said. "It was three times harder to drive this car than last year when we spanked them."

Busch held the lead until Stewart passed him with 24 laps to go. Ambrose and Edwards moved around him shortly after.

Greg Biffle completed the top-five.

Juan Pablo Montoya finished sixth, followed by Kurt Busch, Max Papis, Clint Bowyer and Denny Hamlin.

A spectacular multi-car crash on lap 62 when Kasey Kahne got loose in turn nine and bumped Sam Hornish Jr., who spun hard into the tire barrier. Hornish then bounced back on the track and slammed violently into Jeff Gordon, who hit the barrier head on.

"Kasey got loose and I had to correct," Hornish said. "It got me sideways and I thought the tires are probably going to hurt a little bit. I didn't think I was going to get hit by two more cars."

Both drivers were not injured. Jeff Burton, Joey Logano and road course ringer Andy Lally were also involved in the wreck.

Gordon spent additional time in the infield medical center as a precaution for his recent back problems.

"It's just not what I needed," said Gordon, who finished 37th. "It took a toll on my back again, so I hate that."

NASCAR halted the race 20 minutes for track cleanup efforts.

A similar incident occurred at Watkins Glen last year when David Gilliland smacked the wall in turn 11 and then ricocheted back on the track before slamming into Bobby Labonte. Seven other drivers were also involved in that pileup.

Dale Earnhardt Jr. stuffed his car hard into the tire barrier on lap 42. Earnhardt Jr., who lost his brakes, bumped into Reed Sorenson, with Sorenson sliding into the gravel and it worked for a split second before I blew a hose or a brake line," Earnhardt said.

"Going into (turn) three, I mashed the brakes at Jr. said. "I tried to miss (Sorenson) and couldn't do a good job with that."

Earnhardt Jr. ended up finishing 39th.

With the victory, Stewart padded his lead to 260 points over Jimmie Johnson, who recovered from a mid-race spin to finish 12th. Stewart has essentially secured a spot in the "Chase for the Sprint Cup," as he holds a 756-point advantage over 13th-place Kyle Busch with four races remaining until the playoffs begin in September at New Hampshire.