Houston - Ireland's Paul Dunne made the most of his four remaining holes to be credited as the leader with an eight-under-par 64 after the completed first round of the rain-affected Houston Open on Friday.
Dunne, 25, had moved to six-under-par through 15 holes on Thursday when poor light halted play just after 7.30pm local time and with the tournament having been delayed at the start of play by two hours due to heavy overnight rain.
When play resumed on Friday, the reigning British Masters champion holed a 30-footer for birdie at the par-3 16th hole to join the clubhouse leading duo of Lucas Glover and Kevin Tway at seven-under-par.
Dunne then took the lead and moving to eight-under-par in holing a 13-footer at the par-4 17th before missing the green right at the last only to send a superb chip shot to three-feet from where he holed the par putt.
The quietly-spoken Dubliner secured his place into the event for a first occasion after finishing top-10 in last week's Corales Championship in the Dominican Republic.
The effort is easily Dunne's lowest score, and despite a lift-clean-and-place rule in effect on the saturated Golf Club of Houston course, in 12 PGA Tour counting events dating back to his appearance in the 2014 Open.
It is Dunne's lowest score also this year and a shot fewer than a 65 on day three of Abu Dhabi HSBC Championship in January.
"I'm really pleased as I was playing really well late yesterday and it was only that it started getting dark we had to end play," he said.
"It can always be different then in the returning to the course the next day and trying to continue that form but I did in managing to hole a great birdie on 16 and then to also birdie 17 was great.
"I did leave myself a tricky chip shot on 18 but the ball came out nicely so it delighted to finish with a 64.
"If you keep it on the fairways then the golf course is very much for the taking."
Dunne had around 30-minutes ahead of teeing-off in his second round but played down his chances of securing the last invitation into next week's Masters.
"I can't be thinking of the Masters," he said.
"I was delighted to have qualified for this event in finishing fifth last week in the Dominican Republic and all I am focussed on is doing well this week."
American Sam Ryder had been leading on eight-under-par through 16 holes when play was halted late Thursday but with the 28-year old Florida golfer returning to bogey his closing two holes in a round of a six-under-par 66.
Leading scores after Friday's completed first round of the USPGA Houston Open. (USA unless noted, par-72):
64 - Paul Dunne (IRL)
65 - Lucas Glover, Kevin Tway, Beau Hossler
66 - Rickie Fowler, Rod Pampling (AUS), Julian Suri, Ryan Armour, Sam Ryder
67 - Padraig Harrington (IRL), Seamus Power (IRL), Bud Caulay, Keith Mitchell, Greg Chambers (AUS), Michael Thompson, Brett Stegmaler, Jason Kokrak, Shawn Stefani, Matt Every, Grayson Murray, Steve Stricker, Brandt Snedeker.