In-form Justin Thomas became only the seventh player to break 60 on the PGA Tour, and the youngest in that elite club, with a stunning opening round of the Sony Open in Hawaii.
Just four days after clinching his third PGA Tour title at the SBS Tournament of Champions on the Hawaiian island of Maui, the 23-year-old American rolled in a 15-foot eagle putt on his final hole, the par-five ninth, to card a 59.
Thomas, who set the tone for his memorable day at Waialae Country Club Honolulu by eagling his opening hole with a chip-in from 34 yards, also carded eight birdies and a lone bogey to become the youngest member of the 59 club.
His lone blemish came at the 11th - his second - but he hit back to birdie eight of the next 10 holes before his superb three at the last capped a sensational round.
Thomas is also the second player to have achieved the feat with an eagle at his final hole, matching the achievement of David Duval when he closed with a 59 to win the Bob Hope Chrysler Classic in 1999.
"It was obviously a fun day," said Thomas. "I just kind of had it rolling out there. All my birdies were easy, it wasn't like I made any long putts or anything."
Thomas made a crucial par save from 10 feet at the eighth - his 17th - before finding a fairway bunker with his drive at the ninth, but he made good connection with a five-iron from the trap and backed up the shot with a perfect putt.
"That save on eight was huge," he added. "It gave me a chance because I knew if I hit a good drive on nine I was going to have a seven or eight-iron in. I missed carrying the bunker by six inches!
"I wasn't too nervous over the putt, I was just focused on making it. I got more excited from seeing them get excited than I did my putt going in.
"But it's not like winning the tournament you know. It's an unbelievable round, but you have three days left still. So I didn't really know how to react."
New US Ryder Cup captain Jim Furyk shot a record 12-under 58 at the Travelers Championship last year, and he is the only player to break 60 twice on Tour having shot a 59 four years ago.
Al Geiberger in 1977 was the first player to post 59 on the PGA Tour, followed by Chip Beck (1991), Duval (1999), Paul Goydos (2010), Stuart Appleby (2010) and Furyk (2013).