DAYTONA BEACH, Fla. — It was another frantic Sprint Cup finish at Daytona International Speedway.

Tony Stewart emerged the winner of the Coke Zero 400, charging past Daytona 500 winner Matt Kenseth on the last lap and holding on as the challengers stacked up behind him Saturday night in one of Daytona's trademark wrecks.

"I don't even remember what happened that last lap," said Stewart, who now has 18 victories at Daytona, second only to the late Dale Earnhardt.

Stewart qualified second but started near the back of the field because his time was thrown out by NASCAR when his Chevrolet failed inspection. He rode around in the back for much of the event, letting Roush Fenway Racing teammates Kenseth and Greg Biffle of Vancouver, Wash., control the front.

"We were going to try to win the thing and be there at the end," Biffle said. "We were right there."

The Roush drivers thought they had the field covered, and probably still liked their chances on the final green-white-checkered restart. Kenseth was the leader with Biffle on his bumper, as second-place Stewart was lined up with Enumclaw's Kasey Kahne.

Kenseth and Biffle pulled away for a lap, but Stewart came quick on the outside, moved to the front, then crossed down the track in front of Kenseth for the lead. Seconds later, Biffle seemed to wiggle in traffic and cars began wrecking all over the track.

"I'm not really sure what happened, they just started wrecking behind us," said Kenseth, who started from the pole in his bid to become the first driver since 1982 to sweep the two Daytona races in the same season.

"It seems like we always end these things in green-white-checkers, and whenever you do, really anybody that's in the front few tandems has a shot to win the thing. It's so unpredictable. You do things those last two laps that you'd never do the rest of the race. It's really hard to figure."

The final results showed Jeff Burton came from nowhere to finish second in a Richard Childress Racing Chevrolet, followed by Kenseth in a Ford and Joey Logano in a Toyota.

Stewart teammate Ryan Newman, who was involved in a pit-road incident with Kahne and Jeff Gordon, finished fifth. Roush driver Carl Edwards was sixth and was followed by Kahne, Brad Keselowski in a Dodge and Michael Waltrip. Bobby Labonte rounded out the top 10.

Biffle, who was in third on the final restart, dropped all the way to 21st and said the accident started when Dale Earnhardt Jr. gave Kevin Harvick a big push, and Biffle turned in front of Harvick.

"He got a hell of a shove off the front of Junior. ... I'm like, 'It's impossible that somebody could get into that hole that quick,' " Biffle said. "But he got squirted off the bumper of (Earnhardt) and shot in there. It was my fault."

Earnhardt finished 15th in the 43-car field.

Stewart, meanwhile, picked up his third win of the season, which ties him for the most in the Sprint Cup Series with Keselowski. The defending series champion has won this race at Daytona four times in his career, all within the last eight years.

Notes

• NASCAR temporarily suspended driver AJ Allmendinger for a failed drug test. Allmendinger's "A" sample taken last weekend at Kentucky Speedway came back positive, and the driver has 72 hours to request his "B" sample be tested.

"NASCAR has a strict drug-testing program that Penske Racing fully supports. Penske Racing will work with NASCAR through this process and its next steps," the team said in a statement.