WATKINS GLEN, N.Y. -- Slipping and sliding around oil-spattered Watkins Glen International on the last lap and fighting for the lead, Marcos Ambrose and Brad Keselowski didn't know what lay around the next turn.
"It was absolutely chaos at the end," Ambrose said. "I had really burned off the brakes. I couldn't figure out where it (the oil) was coming from. It was just absolutely crazy at the end."
Ambrose finally passed Keselowski heading to the final turn in a stunning fender-banging duel to win the Sprint Cup race at Watkins Glen International for the second straight time.
The oil had been spewing from the No. 47 of Bobby Labonte and ruined the day for Kyle Busch, who seemingly held a commanding lead heading to the white flag of the Finger Lakes 355.
"In the end, nobody knew what was going on," said Richard Petty, owner of Ambrose's No. 9 Ford. "They were slipping and sliding off the race track. Marcos might have known a little bit about it, but the rest of us didn't. Marcos stayed with it all day. Everything fell our way."
It didn't for Busch, who led 43 laps.
"Kyle hit the oil," said Dave Rogers, crew chief of Busch's No. 18 Toyota. "The 47 broke. You can see him, he just went by smoking. He left oil down all over the track. Kyle hit the oil and it allowed the 2 (Keselowski) to get to us."
Desperate for a win to move back into contention for the Chase for the Sprint Cup championship, Busch skidded sideways coming out of the first turn of the final lap. Keselowski's No. 2 Dodge caromed off the side of Busch heading uphill through the high-speed esses and Ambrose followed Keselowski through as Busch spun to the side.
"Busch slipped up big in turn one," said Keselowski, who suffered damage to the front of his car. "There was nothing he could do. We all checked up and Marcos was right on my bumper. We all just about spun out. We got to the inner loop, and again nothing but oil."
Skidding around the 11-turn, 2.45-mile layout, Ambrose and Keselowski battled side by side nearly all the way around. Both even went into the grass in the inner loop at the top of the esses but kept charging.
"I knew there was oil all over the bus stop (inner loop)," winning crew chief Todd Parrott said. "It looked like the cars went through the grass because there wasn't any oil."
Ambrose slipped again in turn 10, but Keselowski couldn't drive past. Neither gave ground, and Ambrose forged ahead on the final turn, another hard right-hander, and turned away Keselowski's final charge on the outside.
"I must have hit the oil one more time and he didn't," Keselowski said. "I thought I had him."
Busch was not available for comment after the race.
Entering the race, Ambrose had one win and had never finished lower than third in four starts at The Glen for an average finish of 2.3 and an average green flag speed of nearly 120 mph. Both were tops in the series.
Jimmie Johnson was third to gain the points lead by one over Greg Biffle. Sonoma winner Clint Bowyer and Sam Hornish Jr. were next, giving Dodge, which is leaving NASCAR at season's end, two in the top five. Dale Earnhardt Jr. spun late and finished 28th to fall from first to fourth in points, 17 behind Johnson.
Biffle was sixth, and Busch, Matt Kenseth, Regan Smith and Martin Truex Jr. rounded out the top 10. Ryan Newman finished 11th to move back ahead of Jeff Gordon into the second wild card slot. Kasey Kahne, who has two wins, holds the other. Gordon was also a victim of the oil, spinning late and dropping to 21st after having driven past Newman.
The top 10 drivers in the standings qualify for the 10-race Chase, and two wild cards are awarded to the drivers with the most wins outside the top 10 -- provided they finishing 20th or higher in points.
Polesitter Juan Pablo Montoya, who broke the track record in qualifying, finished 33rd after being forced to pit when something broke in the right front of his No. 42 Chevy a third of the way into the 90-lap race. He had tracked Busch for the first 26 laps.
Last year, Ambrose beat Busch and Keselowski on a paint-trading, two-lap dash to the checkered flag. Ambrose passed Keselowski for the lead on the final lap and secured his first Cup victory when a violent crash involving David Reutimann and David Ragan precipitated a caution that prevented Keselowski from making one final challenge.
Busch had the lead in that race, and he learned his lesson well. With all three up front again on a restart Sunday with 16 laps remaining in the 90-lap race, Busch dived from third to first on the inside of the 90-degree right-hander, outbraking both Ambrose and Keselowski to take the lead for the first time since lap 26.
Busch, who took the lead from Montoya as soon as the green flag flew, kept Keselowski at bay off his back bumper, with Ambrose seven car lengths back, and pulled out to a 1-second lead as Ambrose challenged Keselowski for second.
Ambrose finally got past him in the inner loop on lap 81, but he was 2.3 seconds behind Busch and seemingly running for second until the dramatic finish.
"I managed to fight my way past Brad and then I tried to chase Kyle down, but he wasn't making any mistakes and he had a fast car," Ambrose said. "I just burned my stuff up trying to get to him. I was thinking, 'OK, it may be second place here.' But then the oil came down and I slipped to third and I thought, 'That's not the plan.' So I just put my head down and just kept trying."