Marcos Ambrose passed both Kyle Busch and Brad Keselowski on the 90th and final lap on Sunday at Watkins Glen to take the checkered flag.  It's Ambrose's second-career victory with the other also coming on the 11-turn road course a year ago.  Keselowski made contact with Busch on the final lap after the 18-car had slid off the track.  Busch ended up finishing seventh, while Keselowski was six-tenths of a second off the pace and came in second.  Jimmie Johnson finished third followed by Clint Bowyer, who won the first road-course race of the season in June at Sonoma.  Sam Hornish Jr. was fifth while Greg Biffle finished sixth.