Jimmie Johnson drives during the NASCAR Sprint Cup Series auto race, Sunday, June, 20, 2010 in Sonoma, Calif. (AP Photo/George Nikitin)
SONOMA, Calif. -- Marcos Ambrose was easily in command at Infineon Raceway when his crew tried to tell him what a good job he was doing circling the scenic road course.
"Stop talking to me!" he screamed over his radio.
Those nerves should have been a sign of things to come as Ambrose made a late-race gaffe that cost him his first career Sprint Cup Series victory and instead gave Jimmie Johnson his first win on a road course.
Ambrose stalled his engine while trying to conserve gas under caution Sunday, and his car came to a stop while leading with six laps remaining. He restarted and tried to re-claim his position at the front of the field, but NASCAR ordered him back to seventh place and Johnson inherited the lead.
Johnson then cruised to the win, while Ambrose had to settle for a disappointing sixth-place finish.
"My bad," the Australian said. "I'm disappointed. It's NASCAR's house and I'll always play by the rules. I don't agree with it, I don't like it and that's only because I lost the race because of it.
"I had the motor turned off trying to save a bit of fuel and just had trouble getting it fired again. That's it."
It was yet another cruel defeat for Ambrose, a road racing ace who has fallen short of victory several times in NASCAR because of various reasons.
He was spun by Robby Gordon while leading the Nationwide Series race at Montreal in 2007, and last year was passed by Carl Edwards in the final turn at the same track. Although he has two career Nationwide wins on the road course at Watkins Glen, he's winless in the Cup Series despite three top-three finishes in five career road course races.
"I feel bad for him," Johnson said. "It was definitely a gift kind of handed to us."
The four-time defending series champion won for the fourth time this season, but first since Bristol in March -- a 10-race drought that had many wondering why Johnson was "slumping."
Aside from ending the slump, Johnson more importantly added a road course victory to his resume and knocked Sonoma off the list of five active Cup tracks where he had never been to Victory Lane.
But road course racing has never been his strength in NASCAR. He went into Sunday's race with an average finish of 17th at Sonoma, which caused him to enter two Grand-Am races this season in an attempt to gain extra practice at making right and left turns.
"I'd say the bottom line to it is I love road course racing. I always have. I grew up racing off-road trucks, made a name for myself in that style of racing," he said. "To come into the Cup Series and not have success early irritated me. That's why today is so special to us, why it has meant so much."
Although Johnson led 55 of the 110 laps, it was Ambrose's race to lose at the end.
Ambrose, who led 35 laps, had a comfortable lead over Johnson when Brad Keselowski's spin brought out the late caution. Instructed by crew chief Frank Kerr to conserve fuel in case the race went into NASCAR's version of "overtime," Ambrose began flipping his motor on and off at various points around the race track.
Unable to get it restarted at one point, his Toyota stalled and Johnson led a handful of cars around him. NASCAR ruled Ambrose failed to "maintain reasonable speed" and dropped him to seventh, where he had blended back into line after re-firing his motor.
Kerr visited NASCAR officials after the race, and said he understood the ruling. But asked if he was "content" with the ruling, he said only "no comment."
Kerr also asked Sprint Cup Series director John Darby about the 2007 race at Kansas, where winner Greg Biffle appeared to run out of gas under caution on the final lap and was passed by Clint Bowyer and Johnson before the finish line.
"I asked John about that, and that's OK. And then I asked if it's OK to get pushed around, so I'm not really sure what the difference is," Kerr said. "Depends on who you are, I guess."
Darby said the Biffle situation was different because Biffle's car continued moving and the two cars behind him sped up to make the pass.
"Biffle maintained pace, the other cars picked up 20 miles per hour," Darby said of the 2007 incident. As for Ambrose, "I don't know what happened, I don't know if his car quit, if he shut it off. What I do know is he was leading, he pulled over, he stopped and he pulled back in and at that point, that's where he is."
Although the Biffle race was confusing at the time -- even third-place finisher Johnson that day questioned the call, "He clearly ran out of gas. If you can't maintain pace car speed, then the guys that can finished ahead of you" -- Johnson on Sunday said the situations were clearly different.
"You've got to maintain a reasonable speed. I thought it was pace car speed," he said. "So when you look at (Ambrose) coming to a stop, I think it really eliminates the gray area or the discussion of, 'What is a reasonable speed?'
"When you come to a dead stop on the racetrack, I think that changes things, makes it black and white, very easy to read the rule."
Robby Gordon finished second in a Toyota for his highest finish of the season, and series points leader Kevin Harvick was third in a Chevrolet. Defending race winner Kasey Kahne finished fourth in a Ford and Jeff Gordon rounded out the top five.
Biffle was seventh and was followed by Boris Said, Tony Stewart and Juan Pablo Montoya.