Singh, a shot behind leader Billy Andrade after the third round, took a two-stroke lead over Brett Quigley with a 25-foot birdie putt on the 218-yard 16th and added a birdie on the par-5 18th to finish at 10-under 274.
The 43-year-old Fijian won for the first time since the Buick Open last July to raise his PGA Tour victory total to 29 and tie Sam Snead's tour record for victories over 40 with 17. Singh won after failing to finish under par in his previous three tournaments, the first time he had done that in regular PGA Tour events since 1998.
Singh had only one birdie in the first 15 holes with the wind swirling through the trees at 10-15 mph and gusting to 20-25 mph, a two-putt birdie on the par-5 fifth.
Adam Scott eagled the 18th -- his second eagle of the day -- for a 70, while Quigley shot his second straight 70 to join Andrade (72) at 7 under. Tom Pernice Jr. (67), Jeff Sluman (68), Luke Donald (70) and Fredrik Jacobson (71) tied for fifth at 6 under.
Scott holed a 30-yard pitch on the difficult par-4 11th to take the lead at 9 under, but dropped a stroke on 13 after hitting his drive into the left rough, and three-putted the 14th from inside 5 feet to fall to 7 under. He followed with a double bogey on 16 before birdieing the 17th and holing a 25-foot eagle putt on 18.
Quigley, winless in 268 PGA Tour starts, made a 20-foot birdie putt on No. 10 to tie Singh and Scott for the lead at 8 under before falling back with a bogey on the 13th after hooking his drive into the trees. He parred the final five holes.
'I played pretty well,' Quigley said. 'I hung in there.'
Pernice, playing in threesome with Masters champion Phil Mickelson, took the lead at 8 under with a sand-save birdie on the par-5 ninth, his third straight birdie in a front-nine 30. He had three bogeys and a birdie on the back nine to finish at 6 under.
'I hit some really nice iron shots,' Pernice said.
Mickelson shot a 72 to finish at 1 under in his final tournament round before the U.S. Open at nearby Winged Foot. He has won the last two majors.
Singh earned $1,035,000 from the $5.75 million purse. ... Padraig Harrington, the 2005 champion, closed with a 72 to finish at 2 over. He opened with rounds of 74, 66 and 75. ... Loren Roberts, a three-time winner this year on the Champions Tour, closed with a 71 to finish 1 over in his fourth PGA Tour start of the season.