Trevor Foster played one of the rounds of his life to leave the international field trailing in his wake at the 50th Seniors Amateur Championship at Royal Porthcawl in South Wales.
The 58-year-old Lancastrian from the Accrington and District club bagged ten birdies and dropped just one shot over the 6,776 yards of the fearsome links to be round in 63, seven clear of his nearest rivals.
"I'm a bit in a daze to be honest," said Foster, as he came out of the scorers' cabin.
"I felt good out there today and hit it really, really well. Probably one of the best rounds I've ever played," said the retired club greenkeeper, who paid tribute to his former Lancashire team mate and captain Bill Bromilow, who was on his bag.
"He's had all the numbers right for me. I've just had to hit the ball."
With a stiff breeze blowing off the Bristol Channel when Foster teed off at 9am he was soon into his stride with a birdie at the 374 yard first, hitting driver and a wedge to 10ft and holing the putt.
He didn't pick up his next birdie until the 385 yard sixth with a 3-wood and a wedge to five feet, then he parred the short seventh before bagging four more birdies on the bounce.
He hit, driver, 3-wood and pitch to a foot to birdie the par five eighth, then driver and 8-iron to 15ft at the ninth to be out in 32.
Foster on fire
Driver, pitch to 6ft and one putt got him started on the back nine, before he hit his 6-iron to 60ft on the shorth eleventh and sank it.
He could only manage a par at the long 12th but then birdied the 438 yard 13th with a driver and a 7-iron to a foot. It was driver and 6-iron to 6ft on the 15th and another one putt before he dropped his only shot at the 16th.
His 3-wood off the tee found a poor lie in the fairway and he could only advance it 80 yards. His pitch third finished 15ft away and he took two putts.
Unfazed he finished in style with birdies at the two closing holes.
A drive and a 5-iron got him to the front of the long 17th and he had two putts from 60 ft, then a drive and an 8-iron finished on the front fringe at the last and he holed it from 20ft.
Winner of the Irish and West of England Seniors already this year, Foster, a former Lancashire champion at open and senior level, is playing in his third Seniors Amateur.
"I was eleventh I think at Formby and then missed the cut at Sunningdale last year when I got the worst of the weather."
Three players are in joint second place on two under par seven strokes behind Foster.
Gene Elliott from Des Moines, Iowa along with fellow American Todd Hendley from Columbus, North Carolina and East Kilbride teacher Ken Gallagher, playing in his first Seniors Amateur championship.
Elliott, joint runner-up at Sunningdale on his first appearance in the Seniors last year, finished the front nine with three birdies after dropping a shot at the fifth to be out in 34 and he was level on the way home with a bogey at the 14th and a birdie at the 17th.
Hendley had birdies at the first, sixth, eighth, 12th and 17th and dropped shots at the second, 13th and 15th.
Gallagher was out in 33 with a birdie at the sixth and an eagle at the eighth, then dropped shots at the 14th and 16th and birdied the 17th on the way home.
Two former three-time winners of the Seniors, Americans Chip Lutz and Paul Simson shot 72 and 76 respectively, while last year's winner at Sunningdale Bryan Hughes from Hesketh in Lancashire opened with a 79 and 2014 champion Brady Exber from the US had a 74.
Three players are on 71 and nine on level par 72 with the top 60 and ties after the second round going through to play the final 18 holes on Friday.