Canadian Adam Hadwin became the eighth player to break 60 on the PGA Tour, and the second in successive weeks, with a superb 13-under-par display in the third round of the CareerBuilder Challenge in La Quinta, California.
Just nine days after American Justin Thomas fired an opening 59 at the Sony Open in Hawaii, Hadwin followed suit at La Quinta Country Club, one of three venues hosting the pro-am event in the Coachella Valley where low scoring is a perennial factor.
The 59 vaulted the Canadian into first place on the leaderboard at 17-under par, one stroke clear of the American, Dominic Bozzelli, who carded a 69 to maintain second place.
New Zealand's Danny Lee was tied with Bozelli for second when the round commenced but a four-over par 76 caused him to tumble into a tie for 21st at nine-under for the tournament.
His compatriot Steven Alker fared better with a 68 on day three and is now level with Lee.
Kiwi Tim Wilkinson also carded red figures today with a 70 to be at seven-under par.
Asked to assess the quality of his golf at La Quinta, Hadwin told Golf Channel: "Perfect I guess?
"I got away with a few shots on the back (nine) and, for whatever reason, whenever I hit a putt, it went in ... I legitimately thought about it (shooting 59) on 11, walking off (the green)."
The 29-year-old from Saskatchewan, who has yet to win on the PGA Tour, reeled off six consecutive birdies from the second hole as he raced to the turn in seven-under 29. He then plundered five in a row from the 11th.
After narrowly missing a birdie attempt at the 16th, Hadwin struck a brilliant approach to five feet at the par-four 17th and coolly knocked in the putt to tie a PGA Tour record with his 13th birdie of the round.
American Chip Beck was the first player to do so, piling up 13 birdies to fire a 59 in the third round of the 1991 Las Vegas Invitational.
Hadwin did well to salvage a par at the 18th, getting up and down from just off the back of the green to remain at 13 under for the day, take the tournament lead on 17-under 199 and become the latest member of the '59' club.
Asked whether he had felt nervous coming down the stretch, Hadwin said: "I was pretty good. I didn't hit a very good tee shot on 16 ... a little longer back than I wanted to but I hit a great iron shot in there.
"That settled me down again a little bit. And then once the putt rolled in on 17, that helped as well."
Jim Furyk broke golf's magic number when he shot a record 12-under 58 at the Travelers Championship last year, becoming the first player on tour to break 60 twice.
Al Geiberger in 1977 was the first player to post 59 on the PGA Tour, followed by Beck (1991), David Duval (1999), Paul Goydos (2010), Stuart Appleby (2010), Furyk (2013) and Thomas last week.
- Reuters, RNZ