Akron - Ireland's Shane Lowry shot a bogey-free four-under 66 Sunday to come from behind and beat Bubba Watson by two strokes to claim the WGC-Bridgestone Invitational on Sunday.
It marked the first victory for Lowry since winning the European Tour's Portugal Masters in 2012 and his maiden win on US soil.
"I can't believe I am standing here as champion," Lowry said. "I played as good of golf as I have ever played the last four days.
"I managed to hole a few putts and get a bit of luck."
The 28-year-old Lowry sank four birdies including a 10-foot putt on the 72nd hole to finish with an 11-under 269 total in the final tune-up before the PGA Championship at Whistling Straits.
Two-time major winner Watson matched Lowry's 66 on Sunday but finished two strokes back with a nine-under 271.
It was another disappointing finish at the Firestone Country Club for American Jim Furyk who finished in the top 10 for the 10th time but is still seeking his first WGC-Bridgestone victory.
Furyk fired a two-over 72 and tied England's Justin Rose (72) for third place, four strokes back of Lowry.
Reigning US Open and Masters champion Jordan Spieth closed with his best round of the tournament by shooting a four-under 66.
Spieth rolled in six birdies Sunday and said he even though he is not playing his best golf right now he is ready for the challenge of trying to win his third major of the season in Wisconsin.
"Going into the US Open and going into the Masters, I maybe felt even more confident about my game than right now... but that can change in a couple days," he said.
Lowry began his final round two shots off the pace set by third round leaders Rose and Furyk.
He wiped out that gap with birdies on the No. 2 and No. 8 and then took a two-shot lead with another birdie after the turn at No. 10.
Lowry held onto his two shot lead with a brilliant par save from 20 feet on the 14th after finding a fairway bunker with his drive.
Lowry moved to 11-under par when he sank his birdie putt at the last to win his first WGC title.
Lowry follows Northern Irishman Rory McIlroy in winning the WGC-Bridgestone but seemed nonplussed about two Ireland players going back-to-back.
"I don't care really who won it last year," Lowry said. "I won it this year and that's all that matters to me."
Robert Streb (66) came in fifth at 274. Brooks Koepka (69), Sweden's Henrik Stenson (70) and David Lingmerth (68), and New Zealand's Danny Lee (68) tied for sixth at 275.
Spieth tied Rickie Fowler (67) for 10th place. British Open champion Zach Johnson closed with a 71 and tied for 33rd place at 282.
Leading scores from the fourth round of the $9.25m WGC-Bridgestone Invitational at Firestone Country Club here Sunday (USA unless stated):
269 - Shane Lowry (IRL) 70-66-67-66
271 - Bubba Watson 70-66-69-66
273 - Jim Furyk 66-66-69-72, Justin Rose (ENG) 67-71-63-72
274 - Robert Streb 68-70-68-68
275 - Brooks Koepka 69-69-68-69, Danny Lee (NZL) 65-72-70-68, Henrik Stenson (SWE) 68-69-68-70, David Lingmerth (SWE) 70-71-66-68
276 - Rickie Fowler 67-72-70-67, Jordan Spieth 70-68-72-66
277 - Steven Bowditch (AUS) 73-69-63-72, Jason Day (AUS) 69-69-70-69, Soren Kjeldsen (DEN) 69-73-69-66
278 - Patrick Reed 71-67-72-68, Kevin Na 69-70-71-68
279 - Branden Grace (RSA) 73-69-67-70, Danny Willett (ENG) 70-71-69-69, Ian Poulter (ENG) 68-72-65-74, Paul Casey (ENG) 68-73-71-67, Lee Westwood (ENG) 68-70-73-68, Keegan Bradley 69-70-69-71, Russell Henley 70-70-70-69, Graeme McDowell (NIR) 66-71-69-73
280 - Bernd Wiesberger (AUT) 71-74-66-69, Webb Simpson 68-70-72-70, Marc Warren (SCO) 71-70-69-70, Matt Kuchar 72-68-72-68, Bill Haas 74-69-67-70, Camilo Villegas (COL) 75-69-71-65