Adam Scott surrendered a three-shot lead but fought back to earn a play-off victory over Ryan Moore in the EDS Byron Nelson Championship.
Former United States amateur champion Moore started the day three shots behind third-round leader Scott but carded a 68 to finish on seven-under.
The Australian surrendered the lead after dropping three shots in his first five holes - his first swing of the day was a nasty hook into the left rough which led to a bogey on the first - but he was back in front after Moore dropped shots at 13 and 14.
The pendulum swung back Moore's way when he holed a 12-foot birdie putt at the par three 17th after making birdie at the par-five 16th.
Almost simultaneously, Scott missed a 10-foot eagle putt at 16.
The 25-year-old Moore made a clutch five-foot par putt on the final green, leaving Scott needing a birdie at 18 to force a play-off.
The Australian drove the ball 320 yards down the fairway and hit a gap wedge to eight feet, then rolled in the birdie putt.
Both men made regulation pars when they played the 18th again, but Scott fired his approach to the par-three 17th to 12 feet and missed the putt to win and Moore did well to two-putt from 70 feet.
The pair went back down 18 and Scott looked to be in trouble in a fairway bunker, but he found the green and then rolled in a 48-foot birdie putt to win.
Spaniard Sergio Garcia - winner in 2004 - started the day four shots off the pace and after a 65 on Saturday had realistic hopes of making a charge for a first title of the season.
But last year's runner-up dropped six shots in his first five holes and struggled round for a 75.