Early finisher Scott posted a five-under-par 66 at Liberty National for an 11-under-par total of 273 that stood up as Tiger Woods (69), U.S. Open champion Justin Rose (68), Canadian Graham DeLaet (65) and Gary Woodland (73) all finished one stroke back.
It was Scott's first victory since his rousing playoff win over Argentina's Angel Cabrera at Augusta, and a frustrating loss for his pursuers, particularly Woods.
Woods, who complained of a sore back this week after sleeping on a soft hotel bed, collapsed to his knees after striking his second shot on the par-five 13th hole and grabbed at his back.
The shot sailed left and into a pond beyond the tee box at an adjacent hole. Woods went on to bogey that hole and the 15th as well before bouncing back with birdies at 16 and 17. He left his last birdie try two revolutions short of the cup.
Rose needed two putts from 30 feet at the last to tie Scott, but sent his 30-foot birdie try five feet past and missed the par putt.
Woodland had 10-foot birdie attempts at both 17 and 18 to join Scott on 11-under but missed both.
Tied for sixth place at six under par were British Open champion Phil Mickelson, who fired a final-round 65, and fellow-Americans Jim Furyk (69) and D.A. Points (67).
The top 100 on the FedExCup points list advanced to next week's playoffs event, the Deutsche Bank Championship in Boston.
(Reporting by Larry Fine, Editing by Gene Cherry)
