LAS VEGAS (AP) — The celebration of Carl Edwards' second consecutive victory was short-lived: His winning Ford Fusion failed a post-race inspection at Las Vegas Motor Speedway that could lead to severe penalties for his team.

NASCAR officials discovered the lid was not on the oil tank box of his race-winning car and the parts are going back to North Carolina for further inspection.

Just last month, five Nationwide Series crew chiefs were suspended for six races, fined $15,000 each and their drivers were docked 25 points apiece because their lids were simply loose.

Bob Osborne, crew chief for the No. 99 Ford, declined comment on NASCAR's discovery. But the infraction could spoil what's been a stellar start to the season for Edwards and that team.

Edwards won for the second time in six days — he also won the rain-postponed event at California on Monday — and moved to the top of the points standings for the first time in his career. He has a 21-point lead over Kyle Busch.

"We do this to win. Winning these races is the greatest," Edwards said. "Winning a championship would be the ultimate. What we're trying to do is win the championship this year. That's our No. 1 goal."

To win in Vegas, Edwards had to overcome an early pit road penalty, escape NASCAR punishment on a second pit road mishap, then hold off a rusty Dale Earnhardt Jr. on a pair of late restarts Sunday.

For Edwards, it seemed like a return to his 2005 form, when he finished third in the series standings.

"I think we are close to the form we were in 2005 when it seemed like a Roush Fenway car would win every week," Edwards said.

It was the sixth victory for team owner Jack Roush in 11 races at Las Vegas, and it ended Jimmie Johnson's string of three straight wins in the desert.

Edwards was penalized early in the race when one of his tires rolled away from the team during a pit stop. He then caught a break when it happened a second time, escaping a penalty because NASCAR determined the tire broke free because a television cameraman shooting from inside the box interfered with the crew members.

"When you think you didn't actually break a rule, you have to keep a level head," said Osborne, who immediately climbed off the pit box to make a case against being penalized.

"I wanted to go ballistic and yell and scream and kick and punch and do whatever I had to do to get my way. But I kept a level head and NASCAR reviewed it."

With the decision to not penalize the team, Edwards remained in contention to run for the win. But two late restarts gave the competition a chance to run down his No. 99 Ford.

Kurt Busch's wreck with 11 laps to go brought out the caution, and Edwards was in front of Earnhardt on the restart with five to go. But Earnhardt appeared to spin his tires at the start, and Matt Kenseth and Jeff Gordon had to split his car to avoid running into him.

"I've been out of the game so long," joked Earnhardt, who hasn't consistently run up front for several years. "I ain't had a whole lot of practice out there. I looked like a tool out there."

Once past Earnhardt, Gordon and Kenseth raced side-by-side and Edwards pulled away. Then Gordon drifted into the side of Kenseth's car, starting a spin that led to Gordon slamming into the inside wall. His Chevrolet broke into parts and pieces, and NASCAR had to red-flag the race to clean the debris.

"It's uncharacteristic of Jeff to overdrive or make a mistake like that," said Greg Biffle, who had to avoid the wreckage.

That accident set up a two-lap sprint to the finish, but the wait time cooled Earnhardt's tires and he was unable to mount a charge on Edwards on the restart. Earnhardt's losing streak stretched to 64 races.

"The red flag just really killed us," said Earnhardt, who settled for second. "We were terrible on cold tires. It's real frustrating."

Biffle was third and was followed by the Richard Childress Racing cars of Kevin Harvick and Jeff Burton. Kasey Kahne was sixth, followed by David Ragan, Travis Kvapil, Denny Hamlin and Mark Martin.

Kyle Busch, who was trying to become the first driver to win from the pole at Las Vegas, struggled with adjustments to his Toyota the entire race and had to settle for 11th on his hometown track.

Johnson, the two-time defending series champion, was looking for a fourth straight win in the desert. But his team struggled the entire weekend, he fell two laps down in the race and finished 29th.

Two-time series champion Tony Stewart bruised his foot 108 laps into the race when his right front tire failed and he hit the wall for the second-straight day.

"I was kind of worried, my legs, my entire legs from my hips down were just tingling," Stewart said. "And I had pain in my lower back and that kind of scared me a little bit. I've not had my legs tingle like that before.

"I was kind of worried about, 'What's going on here?'"