TALLADEGA, Ala. -- Tony Stewart, a six-time bridesmaid at Talladega Superspeedway, finally got to Victory Lane at the 2.66-mile track in Sunday's AMP Energy 500. But a controversial finish left rookie Regan Smith shouting, "Stop the wedding!"

In a green-white-checkered-flag finish that took the race two laps beyond its scheduled distance of 188, Stewart was declared the winner, even though Smith crossed the finish line first. With a quarter-mile to go and Stewart protecting the bottom of the track, Smith was forced to dip below the yellow line, which divides the speedway proper from the apron, to complete the final pass for the lead (watch video).

“

I knew where I was going to make my move. I don't know. I was always told that the rule is if you get forced down there, then you are the winner of the race and on the last lap, anything goes.

”

REGAN SMITH

In NASCAR's view, Smith's move was out of bounds, violating NASCAR's rule against improving position by passing below the yellow line. Accordingly, Stewart was awarded the victory, and Smith was demoted to an 18th-place finish as the last car on the lead lap.

Smith thought he was within the rules on the pass (watch video), and went with Dale Earnhardt Inc. president Max Siegel to defend himself to NASCAR.

"I knew I was only going to get one shot at him," Smith said. "I knew where I was going to make my move. I don't know. I was always told that the rule is if you get forced down there, then you are the winner of the race and on the last lap, anything goes. That's what I was going with.

"I got forced down there, man, I had a nose inside of him and I could have piled up the whole field."

The ruling gave Stewart his first win of the season and snapped a 43-race winless streak dating to Watkins Glen last year. (watch video). There was concern in his voice as he questioned whether Smith would be awarded the win, but he quickly started the celebration when his spotter gave the "20 is the winner" declaration.

"Man, it's one thing to get back to Victory Lane -- but to do it at Talladega -- this is one of four places I haven't won a Cup race, and talk about one to win," Stewart said. "I wanted to win here for so long."

When Smith crossed the yellow line, Stewart and crew chief Greg Zipadelli were convinced they had won the race.

"I made a counter move when I saw him [Smith] coming and got him committed in one direction and got back down to the line in a hurry," Stewart said.

Stewart said further that he had no qualms about blocking Smith.

"I've lost Daytona 500s, and I've lost races here because somebody blocked," Stewart said. "The nice thing is that I was on the right end of it this time. I have no regrets."

Smith saw it differently.

"They always tell us in the drivers' meeting, if you get forced to the inside, you can go for it, especially on the last lap," Smith said. "I saw the replay when I was pulling in here [to pit road], and I felt like we won that race. I could have caused a big pileup, and you don't want to do that, either.

"The moved worked out just how I wanted it to, so I don't know what else I could have done different."

Several competitors, including Johnson, said they had heard that passes below the yellow line would be allowed within sight of the checkered flag. That notion originally stemmed from a ruling that allowed Johnny Benson to improve from third to second at the finish of the February 2007 Craftsman Truck Series race at Daytona.

NASCAR, however, had the final say, and the sanctioning body's position was clear-cut, though it did appear to contradict statements made by NASCAR spokespersons in the aftermath of the Daytona Truck race.

"You cannot improve your position any time you go below the yellow line," NASCAR vice president of corporate communications Jim Hunter said. "In our judgment, he [Smith] improved his position, and the penalty for that is a pass-through, so he was moved back to the tail end of the longest line, or 18th position.

"At the drivers' meeting, we clearly state that you cannot improve your position by going below the yellow line. We do not feel he was forced below the yellow line. We respect Regan's view, but we made the call, we think it's the right call and the finish is final."

Smith's penalty elevated Dale Earnhardt Inc. teammate Paul Menard to the second position, a career-best for the driver who will leave DEI at the end of the season to join Yates Racing. David Ragan ran third, tying a career best, and Richard Childress Racing teammates Jeff Burton and Clint Bowyer finished fourth and fifth, respectively.

The race had a NASCAR-record 31 lead changes, several tire failures and lived up to its reputation as the "wild card" of the 10 Chase events. Because of its white-knuckle racing conditions, Talladega is the one Chase race every driver fears will ruin his title hopes.

The big Chase winner was points leader Jimmie Johnson, who dodged a succession of wrecks that unfolded in front of him and came home ninth in a car that wasn't as competitive as he would have liked.

With his closest pursuers wiped out in a Lap 174 wreck triggered by Carl Edwards that aslo clobbered the cars of Greg Biffle and four other drivers competing in the Chase (watch video), Johnson leaves Talladega with a 72-point lead over second-place Edwards and a 77-point advantage over third-place Biffle.

"He made a mistake and tore up most of the field," said Kevin Harvick, who also got caught up in the wreck. "It's Talladega, you have a 50-50 opportunity to come here and miss the wreck and [Sunday] we got in it."

Notes: Denny Hamlin sustained an ankle injury during hard contact with the outside wall in Turn 2 on Lap 99 (watch video). He was taken to a local hospital for further evaluation. ... The race produced 28 different leaders, a NASCAR record for all tracks, not just Talladega.

The Associated Press contributed to this report.