WATKINS GLEN -- Kyle Busch led a race-high 49 laps in Monday's Sprint Cup race at Watkins Glen International, but a late caution helped foil his day.
Marcos Ambrose got his chance to win the race -- and took advantage of it -- when Paul Menard, running 14th, blew a tire and crashed on lap 86, bringing out the final caution.
That set up a frantic dash to the finish of what turned into a 92-lap race, as Ambrose beat Brad Keselowski and Busch in a two-lap dash to the checkered flag to win the rain-delayed race.
Busch was in the catbird seat for 18 straight circuits when Menard crashed.
"The last couple of laps I was getting away from him [Ambrose]," said Busch, who moved into a tie with Carl Edwards for the top spot in the points standings. "The last thing I wanted to see was a caution."
Ambrose had won all three Nationwide races he's entered at Watkins Glen, and in three Cup starts here, he's notched one second and two thirds, including an impressive drive from last to third in 2008. His win also atoned for a slip-up a year ago on the road course at Sonoma, when he stalled his car under caution while leading with six laps to go and finished sixth.
He is the 15th different winner in Cup races this year.
Busch, trying to win a second time from the pole at Watkins Glen, led the field to the green flag for the final two laps. But Keselowski, racing with a broken left ankle and trying for his second straight win and third of the season, dove from third to the lead entering the first turn with Ambrose also streaking past Busch.
"Those guys didn't care to give me any room," said Busch, who finished second to brother Kurt here in Saturday's Nationwide race. "There's only one corner you've got to make, and as soon as you make it through that corner and can keep everybody behind, it's smooth sailing from there."
Ambrose then closed on Keselowski in the chicane after zooming through the high-speed esses and passed him for the lead before the final lap.
"I wanted to win," said Keselowski, who has the first wild card for the Chase and moved up four spots in the standings to 14th. "We had a shot at it, and that's all you can ask as a driver."
Kyle Busch finished third, and Martin Truex Jr. and Joey Logano rounded out the top five. Kevin Harvick was sixth, followed by defending race winner Juan Pablo Montoya, AJ Allmendinger and Jeff Burton.
Kurt Busch, who won at Sonoma in June, crashed early and finished 38th. He wasn't alone: Denny Hamlin, who entered the day 11th in points, also crashed and finished 36th; five-time Watkins Glen winner Tony Stewart, who ran up front all race, was taken out on the final lap in the chicane and finished 27th; and Menard, also hunting for a Chase spot, finished 32nd.