Brandt Snedeker enjoyed a historic opening day of the Wyndham Championship as he became only the ninth player to break 60 in PGA Tour history.
Snedeker's astonishing 11-under 59 at Sedgefield Country Club in North Carolina actually began with a bogey at the 10th, but he responded with 10 birdies and a spectacular slam-dunk hole-out for eagle as he raced into a five-shot lead over the field.
The 37-year-old got over his blemish at the 10th and, after two settling pars, a 25-foot putt for birdie at the 13th ignited a run of four consecutive birdies before a pair of pars capped a back-nine 32.
But Snedeker all-round game really caught fire on the outward half as he began to pepper the pins with his precision irons, converting three straight chances from inside six feet from the first to the third.
A good up-and-down for another birdie at the long fifth was followed by the shot of the day, a perfect 176-yard seven-iron which landed straight in the cup for a slam-dunk eagle-two, although he had no idea his ball had found the hole until he arrived at the green to a warm ovation from the growing gallery following his group.
An inspired Snedeker then drilled another pure iron to two feet at the tough 223-yard seventh and tapped in for birdie to get to 10 under for the round, but he then missed a great chance for another at the next when he misread a six-foot putt for a three.
Snedeker's chances of a 59 look slim when his approach to the ninth found the front-right fringe, 20 feet from the hole, but his perfect putt dropped into the centre of the cup to leave the American celebrating the first sub-60 round on the PGA Tour since Adam Hadwin at the CareerBuilder Challenge in January last year.
His incredible run of scoring on the front nine was also only the 12th score of 27 for nine holes on the PGA Tour, and his overall 59 was two strokes better than his career-best 61.
"To step up and have a 20-footer and know what it means, when I knocked that putt in it was really special to know that I'm part of a small club on tour," said Snedeker afterwards.
"It was a crazy day. You start off with a bogey, a snap-hook three-wood off the 10th tee, but I made some long putts on the front nine and got hot on back nine.
"It's very rare out here when you have something to do and you step up with this pressure and you do it. If you don't get excited for that, then you need to find another job.
"To roll that last putt in was such a cool feeling. I got so excited, goosebumps, and jumping around like I won the golf tournament and it's Thursday morning! I'll have to get the emotions in check this afternoon, get back to reality."