Los Angeles - American Collin Morikawa birdied the final three holes on Sunday to win his first PGA Tour title at the Barracuda Championship in only his sixth start as a tour professional.
The 22-year-old, who graduated from the University of California in May, finished on 47 points, three more than US runner-up Troy Merritt in the only US tour event that uses the Modified Stableford scoring system.
The former world amateur number one made his pro debut at last month's Canadian Open, shared second three weeks ago at the 3M Open and shared fourth two weeks ago at the John Deere Classic to secure a spot on next season's tour.
"It was something really special to finally get the win," Morikawa said.
"I think the gates are open. I've been knocking on the door the past month or so. I've been playing well. I just believed in myself, was able to make some shots and come through."
Under the unique format, eight points are awarded for an albatross, five for eagle, two for birdie and zero for par, and a point is deducted for bogey with three deducted for double bogey or worse.
Morikawa birdied seven holes, including four of the last five, without making a bogey to score 14 final-round points for the victory at Montreux Golf and Country Club in Reno, Nevada.
Merritt made a six-foot birdie putt at the par-4 12th for two points to seize the outright lead on 42 points.
Morikawa bounced a tee shot off a tree and into the 14th fairway, then took advantage of the break for a birdie to reach 41 points.
Morikawa sank a 10-foot birdie from the fringe at the par-3 16th to seize the lead, but seconds later Merritt responded with a dramatic 30-foot birdie putt at the par-4 14th to regain a 44-43 edge.
But Morikawa answered with a 30-foot birdie putt of his own at the par-4 17th, regaining a one-point edge over Merritt.
"When I hit it, it was definitely firm but I knew it was a good putt," Morikawa said. "When I hit it I knew it was dead centre. It felt good to make the putt but I knew it wasn't over. I knew I had business to do on 18."
Morikawa tapped in from three feet for another birdie at the par-5 18th for a 3-point edge, forcing Merritt to go for an eagle at 18 to win.
Merritt, who eagled 18 on Saturday, came up 48 feet short of the cup in the fairway on his approach, then rolled his chip past the hole on the left side, clinching Morikawa's victory.
"My heart was beating really fast," Morikawa said of watching the final drama unfold. "It's something I've got to get used to."
Merritt, who failed to get his third PGA title, settled for his best finish of the season at second on 44 points.
Leading scores after Sunday's final round of the US PGA Barracuda Championship at Reno, Nevada, using the Modified Stableford Scoring System that awards and subtracts points for birdies and bogeys (USA unless noted):
47 - Collin Morikawa 13-7-13-14
44 - Troy Merritt 7-12-18-7
40 - John Chin 9-11-11-9, Robert Streb 13-12-10-5
39 - Bronson Burgoon 12-2-10-5
38 - Tom Hoge 13-8-7-10
37 - Charlie Danielson 5-12-10-10, Martin Laird (SCO) 5-12-11-9, Ryan Palmer 8-7-14-8, Roger Sloan (CAN) 10-11-9-7
36 - Sebastian Munoz (COL) 4-8-9-15
35 - Sepp Straka (AUT) 1-14-7-13
34 - George McNeill 6-16-2-10, Josh Teater 10-5-10-9
33 - Russell Henley 3-9-9-12, Chris Stroud 10-8-8-7, Jonathan Byrd 10-7-12-4
32 - Roberto Diaz (MEX) 5-3-8-16, Kyle Jones 5-6-7-14, Chase Wright 7-4-8-13, Peter Uihlein 3-13-9-7, Emiliano Grillo (ARG) 8-8-10-6, Alex Cejka (GER) 6-9-13-4, Cameron Tringale 7-7-15-3