WATKINS GLEN, N.Y. — Slipping and sliding around oily 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."
Ambrose passed Keselowski heading to the final turn of Sunday's Finger Lakes 355 in a fender-banging duel to win the Sprint Cup race at The Glen for the second straight time.
The oil spewed from the engine of Bobby Labonte's car and ruined the day for Kyle Busch, who led at the white flag.
"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 racetrack. Marcos might have known a little bit about it, but the rest of us didn't."
Busch, who led 43 laps, was unavailable for comment but crew chief Dave Rogers said, "The 47 (Labonte) broke. … 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 Championship, Busch skidded sideways coming out of Turn 1. Keselowski's Dodge caromed off of his side Ambrose followed Keselowski through as Busch spun.
"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. Ambrose followed Keselowski into the grass at the top of the esses but both kept charging. After Ambrose got by, he slipped again in Turn 10, but stayed ahead after withstanding one last bump.
Ambrose has never finished lower than third in five starts at The Glen and the Australian, who grew up racing on road courses, owns both of his Sprint Cup victories there.
And he didn't mind the slick conditions at the end.
"A big shout-out to NASCAR," Ambrose said. "A lot of guys are going to say, 'Should they have thrown a caution, or should they not?' but no one wants to see these races end under caution or bunched back up in these two-by-twos (double-file restarts), making a random finish. We had the three fastest cars duking it out for the win. That's the way it should be, and I think they did the right call."
Keselowski also seemed pleased at the outcome.
"It just came down to who was going to slip up last, and I did, and he got by me and won the race," Keselowski said. "But a good show — good beating and banging, and that's the way racing's supposed to be. Just real proud of that race, proud that there is a class-act guy like Marcos that can race that way without losing his cool and intentionally wrecking somebody. That's really cool."
Jimmie Johnson was third to gain the points lead by one over Greg Biffle. Dale Earnhardt Jr. spun late and finished 28th to fall from first to fourth in points, 17 behind Johnson.
Jeff Gordon spun in the final corner, falling to 21st place and out of the second wild-card spot for the Chase. Ryan Newman and Kasey Kahne are the wild cards with four races left in the regular season.