Playing the 18th hole for the third time in less than an hour, the second time in the playoff, Scott hit his tee shot into a fairway bunker to the right. He got his approach to the front side of the green, then rolled the putt over two ridges and into the cup.
Moore still had a chance at forcing another hole, but his pin-high putt from the fringe skimmed just past the cup.
Scott, the Australian star who cut short a post-Masters trip home so not to waste his good play there, blew a three-stroke lead he carried into the final round. But he made the clutch shots when he needed them for his sixth PGA Tour victory, and first this season.
The playoff started with both players making pars, first at No. 18 and then at the TPC Four Seasons signature par 3, the 198-yard 17th hole, where Moore had taken a one-stroke lead in regulation by curling in a 12-foot birdie putt.