J.B. Holmes kept his nerve down the stretch to grind out a one-shot victory ahead of Justin Thomas in the final round of the Genesis Open at Riviera CC in California.
Holmes trailed his fellow American by four shots after the completion of the weather-delayed third round, but that gap was down to one with nine to play after Thomas dropped three shots in four holes from the second.
Thomas' erratic play continued after the turn and a three-putt from eight feet at the 13th led to a double bogey which handed the advantage to Holmes.
The 36-year-old stayed firm and seven closing pars were enough to complete a 1-under-par final round of 70 and secure victory with 14-under 270.
Thomas was second after a closing 75 while South Korean Si Woo Kim came through the field with a 66 to take solo third a further shot back.
Rory McIlroy had a chance to post the clubhouse lead and put pressure on the leaders after playing his first 16 holes in 3-under. He was in good position at the par-5 17th too, but took three to get down from just off the green and then bogeyed the last to finish tied fourth with Aussie Marc Leishman on 11-under.
The final two-ball took five-and-a-half hours to complete their rounds and Holmes came under much criticism on social media for his slow, deliberate play.
"Well, you play in 25-mile-an-hour gusty winds and see how fast you play when you're playing for the kind of money and the points and everything that we're playing for," he said.
"The greens are fast. You can't just get up there and whack it when it's blowing that hard. You've got to read wind and there's a lot of slope on these greens. It's not an easy golf course and you throw in winds like that.
"It was a tough week. I played great all week and luckily at the end I was able to pull it out."
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