Rickie Fowler overturned a two-shot deficit late on to edge Henrik Stenson and claim the Deutsche Bank Championship on Monday.
Stenson finished one stroke behind Fowler on 12-under after firing a one-under-par 70, and the Swede will be left to rue a costly double bogey at the par-three 16th.
Second round leader Charley Hoffman finished in third on on 11-under, with Jim Furyk, Patrick Reed, Hunter Mahan, Sean O'Hair and Matt Jones tied for fourth on eight-under.
World number one Rory McIlroy surged up the leaderboard into a tie for 29th following his five-under-par 66, although it won't be enough to see him retain top spot on the rankings, while PGA Championship winner Jason Day finished in a tie for 12th after recording a final-round two-under-par 69.
Starting out the day one shot behind Stenson, Fowler, who carded a three-under-par 68, started strongly when he converted a 33-foot eagle putt at the second. Two bogeys and a birdie followed to round off the front nine before the 26-year-old made a further birdie at the 11th.
With Fowler still trailing Stenson, the American sank a superb 38-foot birdie putt at the par-four 14th before finishing with four consecutive pars to end on 15-under. But Fowler's consistency would prove enough after Stenson stumbled late on.
Stenson was ahead for much of the day after taking the turn in two-under 34. Two birdies either side of a bogey at the 11th saw the Swede remain in front before it went horribly wrong at the 16th. Stenson found the water from the tee at the par three and could only salvage a double bogey which saw him surrender the lead to Fowler at the most critical of junctures.
McIlroy finished 12 strokes off the lead despite carding a tournament-best 66, which saw him make five birdies on the front nine before sinking a 26-foot birdie putt to start the back nine with a further birdie. However, the Ulsterman let himself down by missing a 10-foot par putt at the 17th to record his lone bogey of the round.
Despite Jordan Spieth missing the cut, McIlroy will surrender his number one ranking to the Texan, although with neither player in action next week, McIlroy will once again ascend to the summit when the rankings are updated next week.
Day, who was coming off consecutive victories at the PGA Championship and The Barclays, produced a closing 69 which saw him rise into the top 20, but finish some nine strokes off the pace.