Just five days after achieving his maiden Sprint Cup victory at Watkins Glen, the former Australian V8 Supercar champion won his fourth Nationwide event on a road course, despite not taking part in either practice or qualifying as he was on Cup duty at Michigan on Friday.
Ambrose's countryman Owen Kelly had qualified the car in ninth, but NASCAR rules state a driver change following qualifying and ahead of the race means being forced to the back of the grid. However the Richard Petty Motorsports racer was already chasing leader and polesitter Jacques Villeneuve halfway through the 74-lap event.
With 30 laps remaining he had his first chance of claiming the lead from his Penske rival, restarting beside Villeneuve following the second caution of the day. But their battle resulted in an incident as Villeneuve ran wide at Turn 1, went through the grass at Turn 2 and crashed against the right-front of Ambrose's Ford.
As both rejoined, Ambrose was quick to retaliate, spinning Villeneuve later on the same lap. Caution periods allowed the Australian to pit for repairs to his car before he put on a further charge to the front, eventually claiming the lead from Villeneuve's team-mate Alex Tagliani on a restart with 10 laps remaining.
A final caution for oil on the track after Robby Gordon's engine blew up following contact with Tagliani put Ambrose under pressure again but he was able to keep his rivals at bay, beating the Canadian by a comfortable margin while avoiding a repeat of the last-corner disaster that saw him lose the race to Carl Edwards with the chequered flag in sight two years ago.
Joe Gibbs Racing's Michael McDowell was third ahead of Steven Wallace, who punted local Patrick Carpentier into a spin which would later cause him to retire from his final career outing. However, fourth was Wallace's best career finish in the Nationwide Series.
Local JR Fitzpatrick rounded out the top-5, Scott Speed was a solid sixth for Kevin Harvick's team, ahead of former series champion Carl Edwards, who also started from the back of the field.
Danica Patrick struggled on her first NASCAR road course event with a long brake pedal hampering a promising strategy. In the end a suspected broken axle meant she limped to a 24th place at the flag.
Polesitter Villeneuve led the most laps but finished 27th and two laps down on winner Ambrose.
