Branden Grace grabbed five of his eight birdies on the back nine on Saturday to pull away for a two-shot win in the Portland LIV Golf Invitational and capture the $4 million first prize.
The 34-year-old ranked 128th in the world pulled level with Carlos Ortiz with a birdie at the 13th, then birdied the 15th, 16th and 17th to secure the win in the second event of the controversial Saudi-funded series, which has raised the hackles of the established US PGA Tour and DP World Tour and sparked criticism over Saudi Arabia's human rights record.
But controversy appeared far from Grace's mind as the celebratory champagne was sprayed on the 18th green at Pumpkin Ridge outside Portland, Oregon.
"This new format, everything is amazing and everybody is having a blast," Grace said after the win in the 54-hole event in which there is no cut and all 48 entrants earn some piece of a purse of more than $20 million.
Grace carded a final-round 65 and finished two strokes in front of Mexico's Ortiz, who closed with a three-under par 69.
Two-time major-winner Dustin Johnson, at 17th in the world the highest-ranked player so far to bolt for the new series, started the day tied for the lead with Ortiz but finished tied for third with compatriot Patrick Reed on nine-under.
Johnson carded a one-under par 71 while former Masters champion Reed moved up with a five-under 67 that included a chip-in eagle at the 17th.
Hours before the event teed off on Thursday, family members of people killed in the September 11, 2001 attacks held a press conference near Pumpkin Ridge to voice their outrage.
Insisting that Saudi Arabia should be held accountable in the attacks -- in which 15 of the 19 hijackers were Saudi nationals -- they joined with human rights groups who say the lucrative series is an attempt to boost the kingdom's image through sport.
The series' Saudi ties also hit close to home in Oregon, where in 2016 15-year-old Fallon Smart was killed in a hit-and-run traffic accident in which Saudi college student Brahmanda Ameer Norah faced a first-degree murder charge.
He removed his monitoring device before his trial and US authorities said they believed the Saudi government had helped him leave the country.
Nevertheless, the golf event drew enthusiastic crowds, organisers saying Pumpkin Ridge was sold out on Saturday without offering an attendance figure.
Grace had taken the outright lead with his birdie at 15 when his tee shot at 16 skipped through the fairway into a strip of rough alongside a cart path.
His second shot went through the green, but he strengthened his grip on the lead by chipping in for birdie.
The team title went to the All-American quartet of Johnson, Reed, Tolar Gooch and Pat Perez, each pocketing $750,000 in addition to their individual earnings.
- Controversy and consequences -
The third LIV Golf event is scheduled for July 29-31 at Trump National Golf Club Bedminster in New Jersey.
England's Paul Casey, ranked 26th in the world, revealed Saturday he had signed up to make his LIV Golf debut there, but the turmoil sparked by the rebel series promises to continue.
The PGA Tour issued suspensions seven members and former members who made their LIV Golf debuts in Portland, including Ortiz, Reed, four-time major-winner Brooks Koepka and former US Open champion Bryson DeChambeau.
And DP World Tour chief executive Keith Pelley slammed players -- including Ian Poulter and Lee Westwood -- who threatened legal action if the fines and suspensions imposed on them after they played the inaugural LIV Golf event in London weren't rescinded.
"Before joining LIV Golf, players knew there would be consequences if they chose money over competition," Pelley said.