GAINESVILLE, 2 Aug 2015, (AFP) - The unheralded 29-year-old held off US star Rickie Fowler and Swede David Lingmerth over the back nine to become the 10th first-time winner on the US PGA Tour this season but the first in the history of the National.
Merritt, who fired a tournament-record 61 on Saturday, finished 72 holes at Robert Trent Jones Golf Club on 18-under 266 for a three-stroke victory over Fowler with Lingmerth third on 270.
"I really made some golf shots coming in," Merritt said. "Battled all the way to the end. Hat's off to Rickie. It's great to battle a great player all the way to the end."
England's Justin Rose, the 2013 winner, shared fourth on 272 with New Zealand's Danny Lee, Sweden's Carl Pettersson and Americans Bill Haas, Justin Thomas, and Jason Bohn. Japan's Ryo Ishikawa was another stroke back in 10th.
Merritt, ranked 180th, had missed the cut in his past five starts. His best prior PGA showing was a runner-up effort last year at Memphis, but he had tied a course record with a 61 at the Heritage in April.
Lingmerth, who won his first PGA title in June at the Memorial, and Fowler, who won the Players Championship in May and the Scottish Open last month, each made two back-nine bogeys while Merritt had only one and matched Fowler birdies at 16 and 18 for the victory.
Tournament host Tiger Woods birdied five of the first 10 holes, including a 42-foot birdie putt at the par-3 ninth, but then made bogeys on three of the next four. He answered with an eight-foot birdie putt at 17 but settled for a 68 to finish on eight-under 276, his lowest 72 holes in relation to par at a PGA event since the 2013 BMW Championship.
"Felt like I made some big strides," Woods said of the week. "It was a mixed bag as far as results but the fact I had total control of the golf ball was nice."
Woods, a 14-time major champion, has slumped to 266th in world rankings due to injuries and swing changes. He has 79 career PGA Tour titles, three shy of Sam Snead's all-time record, but has not won a title since the 2013 World Golf Championships Bridgestone Invitational and has not won a major since the 2008 US Open.
Haas birdied six of the first 10 holes to seize a share of the lead with Merritt, who opened with a birdie, added another at the par-5 fifth and another at the seventh.
But Haas had four bogeys in five holes starting at the 12th to fall out of contention, leaving Merritt to hold off Fowler and Lingmerth.
Merritt missed a 10-foot par putt and made bogey at 12, but at 16-under was two atop Lingmerth after the Swede birdied 14 with Fowler and Pettersson another stroke adrift.
Fowler sank a five-foot birdie putt at the par-3 16th to reach 14 under. Lingmerth reached the clubhouse on 14 under after closing with four pars, while a bogey at 18 ended Pettersson's hopes.
Merritt put his tee shot at 16 only three feet from the cup and birdied to reach 17-under.
Fowler sank a 23-foot birdie putt at 18 to pull within two with Merritt behind him in the fairway but the leader safely reached the green and sank his long putt to win in dramatic style.
Leading scores after Sunday's final round of the US PGA Quicken Loans National (par-71, USA unless noted):
266 - Troy Merritt 70-68-61-67
269 - Rickie Fowler 67-65-68-69
270 - David Lingmerth (SWE) 68-65-68-69
272 - Justin Thomas 66-71-68-67, Danny Lee (NZL) 67-67-69-69, Bill Haas 67-71-64-70, Justin Rose (ENG) 66-71-65-70, Carl Pettersson (SWE) 70-68-64-70, Jason Bohn 67-67-67-71
273 - Ryo Ishikawa (JPN) 63-68-71-71
274 - Chad Campbell 68-70-69-67, Steve Wheatcroft 65-73-68-68, Kim Whee (KOR) 68-66-67-73, Charles Howell 67-67-67-73
275 - Greg Owen (ENG) 66-68-73-68, Brian Davis (ENG) 70-70-66-69, Ollie Schniederjans 66-69-68-72
276 - Tiger Woods 68-66-74-68, Jason Kokrak 71-68-67-70, Kevin Chappell 64-68-67-77
277 - Will Wilcox 68-71-70-68, Jimmy Walker 71-63-73-70, Hudson Swafford 68-72-67-70, Brice Garnett 69-65-72-71, Pat Perez 67-67-72-71, Adam Hadwin (CAN) 67-70-69-71, John Peterson 67-70-68-72, Cameron Tringale 68-69-67-73, Andres Romero (ARG) 69-69-67-72