Washington - Joaquin Niemann carded a two-under par 68 on Saturday and to take a two-shot lead at The Greenbrier, where the 20-year-old Chilean is chasing his first PGA Tour title.
Niemann had three birdies and his first bogey of the week to emerge with a 15-under par total of 195 on the Old White TPC in White Sulphur Springs, West Virginia.
He was two shots clear of Americans Richy Werenski, Nate Lashley and Robby Shelton. Werenski and Lashley both posted 65s while Shelton carded an even-par 70.
It was a further stroke back to Americans Adam Long and Scottie Scheffler on 198.
Kevin Chappell, whose second-round 59 on Friday was just the 11th sub-60 round ever produced on the PGA Tour, struggled in the follow-up.
Chappell, playing his first tournament since having back surgery last November, had four bogeys and one birdie in a three-over 73 that left him eight off the pace.
Niemann, who has eight top-10 finishes in his 42 career starts on the US tour, was coming off a career-best 62 on Friday that left him tied for the 36-hole lead in the first event on the US tour's 2019-2020 calendar.
With the greens firming up and the pins tucked into some tricky positions, super-low scores were less in evidence on Saturday.
After rolling in a 26-foot putt for his second birdie of the day at the 10th, he made his lone miscue, finding the rough off the tee at the 11th on the way to a bogey.
He took advantage of the par-five 17th to stretch his lead, recovering from an errant tee shot to roll in a seven-foot birdie putt.
Lashley, who captured his first career title in Detroit in June, had five of his six birdies in his first eight holes and seized a share of the lead at 14-under with an eagle at the 17th -- where he holed out from off the green.
Moments later play was halted for 50 minutes because of lighting in the area. Lashley would return to make his third bogey of the day at the par-three 18th.
Werenski was delighted to complete his 65 shortly before the weather delay.
"I played good," said Werenski, who said a conservative game plan in tougher conditions paid off.
Knowing that he was putting well, Werenski said, his plan was to "not fire at anything too crazy.
"It worked out," he said.
Leading third-round scores on Saturday in the US PGA Tour's The Greenbrier at White Sulphur Springs, West Virginia (USA unless noted, par-70):
195 - Joaquin Niemann 65-62-68
197 - Richy Werenski 67-65-65, Nate Lashley 68-64-65, Robby Shelton 62-65-70
198 - Adam Long 66-62-70, Scottie Scheffler 65-62-71
199 - Joseph Bramlett 67-67-65, Harris English 66-65-68
200 - Patrick Rodgers 68-66-66, Tom Hoge 68-65-67, Im Sung-jae (KOR) 66-67-67
201 - SebastiAn Munoz (COL) 69-66-66, Mark Anderson 68-66-67, Mark Hubbard 64-70-67, Brian Harman 65-66-70
202 - Scott Brown 66-70-66, Keegan Bradley 67-68-67, Matt Jones (AUS) 68-66-68, Austin Cook 66-68-68, Kevin Na 64-70-68, Scott Harrington 64-69-69, Harry Higgs 67-66-69, Jason Dufner 67-66-69, Bronson Burgoon 65-68-69, Grayson Murray 66-67-69, Lanto Griffin 64-68-70, Morgan Hoffmann 66-65-71, Sam Ryder 65-66-71