Danny Willett suffered a final-hole meltdown as Max Homa retained the Fortinet Championship in California.
Homa chipped in on the final hole before Willett three-putted from close range to finish a shot behind his playing partner.
Willett birdied the first and fourth and when he hung his approach at the eighth up over the flag and watched it trundle back within three feet, a third gain was assured.
He gave that shot back immediately to take some of the shine off a strong outward nine but a 16-foot putt at the 10th curled in and he holed from a similar distance from the fringe of the 14th green for another birdie.
Homa bounced back from two bogeys in the first four holes with three consecutive birdies around the turn, crowned by a 30-foot putt at the 11th.
He came up short with a bunker shot at the last but rattled his chip in off the flag to finish 16-under par and put pressure on Willett’s short birdie putt — and amazingly the Englishman twice lipped out from inside five feet for a three-putt bogey that condemned him to a runner-up finish.
Willett could only laugh at his nightmare finish as he shook hands with Homa, who told Sky Sports: “The last three minutes are kind of a blur.
“I played solid — Danny and Justin (Lower) both played well but that was a wild finish.”
Homa is part of the American team for next week’s President’s Cup and said: “I’ve had a few guys tell me that if the LIV guys hadn’t left I wouldn’t have made the President’s Cup team, so I had a little bit of a chip on my shoulder this week.”
Taylor Montgomery produced the round of the day, eight birdies and no bogeys in a 64 to finish third on 13 under.
Overnight leader Lower, playing in the final group with Willett and Homa, shot 73 to finish alongside South Korea’s Byeong Hun An a shot behind Montgomery.
Open champion Cameron Smith has won his first LIV Golf trophy and $4 million (€4 million) in prize money in just his second start in the competition.
The Australian, who left the PGA Tour for the controversial Saudi-backed tournament after becoming number two in the world — the highest-ranked player to join, closed with a three-under 69 for a three-shot victory at the Chicago Invitational.
The 29-year-old was briefly threatened in the third and final round at Rich Harvest Farms but he restored his lead with a birdie on the 17th to ensure neither Dustin Johnson nor Peter Uihlein could catch him.
The Americans tied for second after each made birdie on the par-5 18th hole. Johnson finished with 70 while his compatriot Uihlein finished with 69 — both earning $1,812,500 from the $20-million purse.
Johnson is the only player from the 48-man field to have finished in the top 10 at every LIV Golf event and he remains one of the most significant players to sign up.
The 38-year-old is a two-time major champion who was number one in the world longer than any player since Tiger Woods.
The next LIV Golf event is in three weeks in Bangkok.
The series does not return to the United States until the final team event at Trump Doral near Miami in October.
As well as Smith and Johnson, the Saudi-backed rebel tour has attracted Brooks Koepka and Bryson DeChambeau.
