AVONDALE, Ariz. -- Not bad, old man.

The 36th victory of Mark Martin's career was perhaps his most fulfilling.

The 50-year-old polesitter streaked away from Tony Stewart after a restart with six laps remaining to win Saturday night's Subway Fresh Fit 500 NASCAR Sprint Cup race at Phoenix International Raceway.

Martin became the oldest driver to win in the series since Morgan Shepherd won at age 51 on March 20, 1993 at Atlanta. Martin's victory was his first since Oct. 9, 2005 at Kansas Speedway and his first since joining Hendrick Motorsports to start the 2009 season.

Stewart ran second followed by Kurt Busch, Jimmie Johnson and Greg Biffle. Denny Hamlin, Martin Truex Jr., David Reutimann, Sam Hornish Jr. and Carl Edwards completed the top 10, as a late caution for an accident involving Dale Earnhardt Jr. and Casey Mears scrambled the finishing order.

"The thought went through my mind -- 1989 with Jack Roush (Martin's former car owner) -- when I got my first win at Rockingham, I said, 'My life is fulfilled,'" Martin said in victory lane. "I thought about saying that again tonight, but I'll stop short of that.

"But it means that much. It means just as much as getting that first one to me. We made a couple of early adjustments, but after that we never made adjustments. There were cars better than us in the middle of the race, but it came to us. At the end, nobody could run with us."

Martin took the lead from Earnhardt with a pass off Turn 2 on Lap 256 of 312 at the 1-mile flat track. He increased his advantage over Stewart to more than four seconds before Earnhardt and Mears tangled in Turn 4 on Lap 301.

Stewart's teammate, Ryan Newman, stayed out on old tires and took the green flag in the lead on Lap 307 but quickly faded. Martin was back in front before the cars got back to the start/finish line and began to pull away. He was .734 seconds ahead of Stewart at the finish.

The race left Stewart still seeking his first victory as an owner/driver at Stewart-Haas Racing, but the runner-up was encouraged by his progress.

"We're so close," Stewart said. "We're going to win one of these soon. (But) I'm glad to see Mark get this win. He deserved it. He had the fastest car."

Series points leader Jeff Gordon took advantage of a pair of opportune cautions to avert disaster -- temporarily -- midway through the race. On Lap 149, contact between Gordon's No. 24 Chevrolet and Denny Hamlin's No. 11 Toyota bent the left front fender of Gordon's car, causing it to rub against the tire.

Gordon began to drop back, but two laps later, AJ Allmendinger's Dodge slammed the Turn 2 wall to cause the third caution of the race. Gordon pitted for repairs on Lap 152, while most lead lap cars stayed on the track, having come to the pits on Lap 139.

On Lap 165, contact from Gordon's Chevy turned Michael Waltrip into Robby Gordon, causing the fourth caution. Earnhardt, Gordon, Marcos Ambrose and David Stremme stayed on the track while the rest of the lead-lap cars came to the pits.

Though Gordon gradually faded on older tires, he remained in the top 10 until his crew failed to secure a lug nut on the car during a pit stop on Lap 233. Having squandered his good fortune, Gordon finished 25th and lost 77 points of his advantage in the standings. He now leads second-place Johnson by 85.

Notes: After his late accident, Earnhardt dropped to 31st at the finish� Kyle Busch beat Stewart out of the pits on the final stop under caution on Lap 302 but was penalized for speeding on pit road. He finished 17th.