Adam Scott sunk a mammoth 49-foot putt to birdie the third play-off hole and claim the Byron Nelson Championship last night, his first PGA Tour title in more than a year.

Scott's putt ensured he defeated Ryan Moore, who had a chance to extend the play-off, but missed his own birdie putt.

"This would have been a tough one to lose, so I was glad I was able to pull this out," the world number 10 said after the victory. "I would have liked to have had a good round like Ryan. He deserved to win, but I am happy to get this one."

Both Scott (71) and Moore (68) finished regulation at seven-under-par 273 after Scott had birdied the 18th to force the play-off.

The Australian missed two chances to win the play-off at the 17th and 18th holes, missing makeable putts before a dramatic final play-off hole, again at 18.

He put his drive into the bunker and left his approach shot short on the front portion of the green before he made the long birdie putt, which generated a massive fist pump by Scott and howls of delight from the gallery.

Bart Bryant finished third on 277.

"This may not have been the message I wanted to send," Scott said of his sixth PGA victory. "But any win is good. I'll probably take more from this one, gutting it out, than winning by five."

Moore, who is still seeking his first PGA Tour title, collected his third second place finish.

"I'm disappointed I didn't make my putt after he made his. But I still got closer than I have in the past, losing in a play-off," he said.

Sergio Garcia finished tied for 19th on 281 and is still to record a top-10 finish this year.

He was six-over after five holes, but mixed four birdies with three bogeys for the rest of the round to finish with a 75.

"I am still encouraged with where I am," Garcia said. "After the fifth hole I played well enough to win today. That's what I will take with me."