GREENSBORO, N.C. — South Koreans An Byeong-hun and Im Sung-jae posted their best scores on the PGA Tour to share the first-round lead at the Wyndham Championship on Thursday as Jordan Spieth displayed a wondrous putting touch to match his lowest score of the season.

An and Im, both bogey-free in ideal conditions for low scoring, carded eight-under-par 62 to head Canadian Mackenzie Hughes, South Africa-born Slovakian Rory Sabbatini and Americans Patrick Rodgers and Johnson Wagner by one stroke.

But nobody provided more entertainment at Sedgefield Country Club than three-times major champion Spieth, who made a couple of unlikely bogeys that complemented six birdies and an eagle in a 64.

Spieth sank a 15-foot putt to salvage bogey at the par-three 12th and, suitably buoyed, played the next five holes in five under par.

But the Texan, whose long game this year has been marred by inconsistency, proceeded to block his drive out-of-bounds at the par-four 18th. Never mind, he duly sank a 20-foot putt to limit the damage to just one dropped shot.

"Sometimes bogey saves are massive. Hopefully, the one on 18 will give some momentum for tomorrow," said the former world number one.

"You want putts for birdie. You want to be hitting greens in regulation.

"I did a pretty good job of that on the back nine until the last hole, but really two bad swings today kept it from being my lowest round on the PGA Tour. There's a lot of good in that."

Spieth is a lowly 67th in the tour's FedEx Cup standings and was a late entry to the tournament, where he hoped to improve his position before the start of the playoffs next week.

He acknowledged that his confidence was still a work in progress.

"I just got real quick (with those bad swings)," he said.

"I know they're still in the bag right now, so I've got a little bit of scar tissue left."

Co-leader An said it had been important to take advantage of calm morning conditions and greens softened by torrential rain on Wednesday.

"The greens were rolling pure, so I needed to make a lot of birdies out there," said the world number 55. "Didn't miss any short putts.

"One good round won't do it, so I need to keep it up and make a lot of birdies. "I've been playing well the last couple weeks, so I like how everything is kind of clicking together, my long game and putting."

Im matched An's score in the afternoon.

"I had a lot of birdie chances. I had a sense this week that I might play well," said the world number 65, speaking via an interpreter.

South African Ernie Els withdrew on his sixth hole because of a back problem. — Reuters