Washington - Dustin Johnson, coming off his first major victory at last month's US Open, fired a four-under par 66 on Sunday to overtake top-ranked Jason Day and win the World Golf Championships (WGC) Bridgestone Invitational.
Johnson birdied three of the last six holes for enough of a cushion to allow for a closing bogey and still win with a 72-hole total of six-under 274 at Firestone Country Club in Akron, Ohio.
"I played good this weekend," Johnson said. "I drove it really well, had a lot of shots from the fairway. I rolled the ball really well with the putter."
Scott Piercy, who finished second behind Johnson at the US Open last month, settled for second again by one stroke after a final-round 70.
Australia's Day, who defends his PGA Championship crown at the end of the month, suffered a late meltdown with a bogey at the par-3 15th and a double bogey at the par-5 16th to help hand Johnson the victory.
"I played pretty good up until the putt on 15. I hit it a little bit hard through the break and that cost me a bogey," Day said.
"Sixteen is always a tough par-5 if you don't get a good drive there... kind of made a mess of it. I really had two bad holes, but really one hole that derailed me, which was 16."
Day finished with a round of 72 to share third with a US trio -- world number two Jordan Spieth, Matt Kuchar and Kevin Chappell.
The results set up an intense showdown in two weeks at the year's third major tournament - the British Open at Royal Troon.
"It's disappointing to not get the win here, but I feel like it's coming around nicely. I'm playing some pretty good golf," Day said. "Disappointed, but I've got to try and focus on what I did great this week, move on, and try and get better for the next one."
It was Johnson's 11th career triumph in a US PGA event, his third in WGC tournaments, and the 32-year-old American's third win a row where he rallied in the final round.
Johnson, three shots behind the lead on Sunday at Firestone, was five adrift entering the final round at the 2015 WGC Cadillac Championship but won and was four off the pace last month at Oakmont before a final-round fightback for his first major crown.
"I feel great," Johnson said. "I feel like my game is where it has been all year. The last couple weeks I've just putted a little bit better and the game shows it."
Day, whose streak of five wins when he led or shared the lead after 54 holes was ended, missed a 4.5-foot par putt at 15 to fall back into a share of the lead with Johnson.
On the tee at 16, Day smacked a tee shot into the trees left of the fairway, then blasted out from under a limb across the fairway and into trees on the right side. He smashed a third shot into a water hazard on his way to a double bogey, falling to four-under.
Johnson, meanwhile, sank a 16-foot birdie putt at 17 and then found himself into the left trees at 18. He clipped a branch on his second shot and landed in dense rough but put his third onto the green and took a bogey that still kept him ahead by two shots over Piercy and Day.
"He played tremendous golf on the weekend," Day said. "Unfortunately I didn't do the best I could to try and beat him."
Both parred 16, meaning they had to make the first eagles at the last at Firestone since 1984 to force a playoff. Neither did as Day went into the rough and made bogey while Piercy put his approach to eight feet and birdied to finish second alone.
Leading scores after Sunday's final round of the World Golf Championships Bridgestone Invitational at Firestone Country Club in Akron, Ohio (par 70, USA unless stated):
274 - Dustin Johnson 69-73-66-66
275 - Scott Piercy 69-69-67-70
277 - Jordan Spieth 68-71-71-67, Matt Kuchar 69-72-70-66, Kevin Chappell 71-70-69-67, Jason Day (AUS) 67-69-69-72
278 - Charl Schwartzel (RSA) 72-69-67-70, William McGirt 64-74-70-70, David Lingmerth (SWE) 70-67-69-72
280 - Zach Johnson 72-74-69-65, Rickie Fowler 68-73-72-67, Adam Scott (AUS) 71-68-73-68, Branden Grace (RSA) 69-72-71-68
281 - Bubba Watson 72-69-70-70, Emiliano Grillo (ARG) 67-71-71-72
282 - Paul Casey (ENG) 70-72-72-68, Matt Jones (AUS) 74-70-69-69, Kevin Kisner 69-70-72-71, Jimmy Walker 67-73-71-71, Brian Stuard 71-69-67-75
283 - Chris Kirk 75-69-73-66, Louis Oosthuizen (RSA) 71-76-67-69, George Coetzee (RSA) 71-72-71-69, Brandt Snedeker 70-72-70-71, Song Young-Han (KOR) 70-70-72-71, KT Kim (KOR) 74-67-70-72