Miami (AFP) - Collin Morikawa fired a three-under-par 69 to clinch a three-shot victory at the World Golf Championships-Workday Championship in Florida on Sunday.
The 24-year-old PGA Championship winner - who led by two after Saturday's third round - relied on accurate iron play and nerveless putting to close out victory at the Concession Golf Club in Bradenton.
Morikawa's final round saw him finish on 18 under with a 72-hole aggregate 270, three shots clear of Viktor Hovland, Brooks Koepka and Billy Horschel on 15 under.
After an early stumble when he bogeyed the par-four second, Morikawa recovered his composure to play flawlessly thereafter.
A 195-yard second shot on the fifth hole left him with a seven-foot birdie putt which he duly rolled in to return to even for the round.
A deft bunker shot on the seventh set up another birdie chance which he converted and he made the turn at two under after making an 11-foot birdie putt on the ninth.
Another birdie putt on the 12th saw him move to 18 under overall and he then rattled off six straight pars down the stretch to bag the fourth PGA Tour win of a professional career that is still less than two years old.
"It shows that I can come out here and compete," Morikawa said after prevailing against a strong field that included nearly every player in the world's top 50.
"What a week. I was working on so much these past couple of weeks. My game felt so good, I'm just so excited right now."
Morikawa is now only the second player after Tiger Woods to win both a major and a WGC title before turning 25.
Woods is currently recovering in hospital in Los Angeles after a serious car crash on Tuesday left him with serious leg injuries.
The Los Angeles-raised Morikawa, who grew up idolising Woods, paid tribute to the stricken former world No. 1.
"Tiger means everything to me," Morikawa said. "Yes, he had the crash and thankfully he's okay and will make a quick recovery. But I don't think we say thank you enough, so I want to say thank you to Tiger."
Earlier, Norway's Hovland had looked poised to challenge Morikawa at the top of the leaderboard after a wild round that included five birdies and a bogey on the front nine.
Two more birdies on the 12th and 13th holes put him at six under for the day but his charge stalled with bogeys on the 14th and 16th.
Koepka meanwhile was unable to put pressure on Morikawa over the closing holes when he missed an easy birdie putt on the 17th which could have put him within two of the lead with one to play.
Koepka, who had been battling neck pain and stiffness since Saturday's third round, closed with a two-under-par 70.
Scottie Scheffler finished alone in fifth on 14 under after a rollercoaster four-under-par 68 which included eight birdies, two bogeys and a double-bogey six.
Scheffler was one of several players who took to the course on Sunday wearing Woods' signature Sunday colours of red and black, in a show of support for the 15-time major winner.
Rory McIlroy, Tommy Fleetwood, Phil Mickelson and Tony Finau were just some of the players who turned out wearing Woods' iconic colour combo.