Hunter Mahan stormed clear of a congested leaderboard with five birdies in the last eight holes to claim his sixth PGA Tour victory by two shots at The Barclays.
Rory McIlroy finished in a tie for 22nd place after a closing one-under-par 70 left him five-under overall.
Graeme McDowell was two shots further back after a final-round 72.
A stroke off the pace heading into the final round, American Mahan sparked his sizzling run by knocking in a five-footer at the par-four 11th and effectively sealed the win at the par-five 17th, where he sank a slick 22-foot putt from above the hole.
He could afford the luxury of a bogey at the last, after pushing his tee shot into a tree line, chipping out and missing the green with his third, as he closed with a six-under-par 65 at Ridgewood Country Club to post a 14-under total of 270.
Stuart Appleby also signed off with a 65 in the opener of the PGA Tour's four-event FedExCup playoffs, finishing joint second at 12 under with fellow Australian Jason Day (68) and American Cameron Tringale (66).