Justin Thomas became only the seventh player to break 60 on the PGA Tour, and the youngest in that elite club, with an 11-under-par display in the opening round of the Sony Open in Hawaii on Thursday.
Just four days after clinching his third PGA Tour title, the 23-year-old American sank 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 in Honolulu by eagling his opening hole, also carded eight birdies and a bogey to become the youngest member of the 59 club.
"I was in an unbelievable zone and very, very focussed," Thomas told Golf Channel after playing the opening round with good friends Daniel Berger and world number five Jordan Spieth, who both carded 65s in ideal scoring conditions.
"I have a good calmness out there and I just feel very comfortable. Unfortunately I know all rounds aren't going to be like today so I've just got to enjoy it while I can."
Asked to describe his thought process as he lined up his eagle putt on the final hole, Thomas replied: "I wasn't thinking a lot. I was just really more focussed on trying to make the putt. Obviously I knew what it meant if I made it.
"That was the first time I had a putt for 59 and I was like, 'Well, who knows if this is going to happen again? I may as well try and knock it in.' And I hit a great putt."
Knowing he had to eagle the ninth to dip under 60, the long-hitting Thomas initially felt he squandered the opportunity when his tee shot found a fairway bunker. From there, however, he hit a stunning five-iron approach from 205 yards to 15 feet.
"I was so bummed on that tee shot," he said. "But I got up there and I had a perfect lie ... and I just hit the perfect shot."
Jim Furyk broke golf's magic number when he shot a record 12-under 58 at the Travelers Championship last year.
Al Geiberger in 1977 was the first player to post 59 on the PGA Tour, followed by Chip Beck (1991), David Duval (1999), Paul Goydos (2010), Stuart Appleby (2010) and Furyk (2013).
(Reporting by Mark Lamport-Stokes in St. Augustine, Florida; Editing by Frank Pingue)