WATKINS GLEN, N.Y. – Slipping and sliding around the oil-spattered Watkins Glen International course on the last lap and fighting for the lead, Marcos Ambrose and Brad Keselowski didn't know what loomed 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 (the oil) was coming from. It was just absolutely crazy at the end."

Ambrose finally passed Keselowski heading to the final turn in a fender-banging duel to repeat as the winner of the Sprint Cup Finger Lakes 355.

The oil had been spewing from Bobby Labonte's car and ruined the day for Kyle Busch, who seemingly held a commanding lead heading to the white flag.

"In the end, nobody knew what was going on," said Richard Petty, owner of Ambrose's car. "They were slipping and sliding off the racetrack. 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, Busch's crew chief. "(Labonte's car) 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 (Keselowski's car) to get to us."

Busch skidded sideways coming out of the first turn of the final lap. Keselowski's car caromed off the side of Busch's heading uphill through the high-speed esses, and Ambrose followed Keselowski through as Busch spun to the side.

"Busch slipped up big in Turn 1," 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.

Ambrose slipped again in Turn 10, but Keselowski couldn't capitalize. Neither gave ground, and Ambrose forged ahead on the final turn 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.

The race also marked Jimmie Johnson's return to the top of the points standings. The five-time season champion fell out of the top 10 two-thirds through the 90-lap race but maneuvered his way back and finished where he started – third.

"I'm excited to be leading the points," Johnson said. "Whoever the team is, I really believe that they get some much-needed experience with the pressure of the points lead late in the season."

Johnson overtook Hendrick Motorsports teammate Dale Earnhardt Jr., who dropped to fourth in the standings. Earnhardt was running as high as seventh two-thirds of the way through the race, but he had a late spin and finished 28th.

"I just got in the corner and made a mistake, and that was pretty much all there was to it," Earnhardt said. "I was just overdriving the car."

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