Harman goes four clear at Texas Open
Harman, chasing his first victory since his 2023 Open Championship triumph at Royal Liverpool, built a 12-under-par total at TPC San Antonio, and was four clear of fellow American Keith Mitchell, who carded an even-par 72.
Harman, who won his lone major title by six shots, said past experience of playing with a big lead would help him at the weekend.
"Just knowing that I've done it before and that it is possible," he said. "It's just left foot, right foot and just take your time getting finished."
Harman opened with a 10-foot birdie at the 10th and added an eight-foot birdie at the 12th.
After a bogey at 16 he reeled four birdies in a row, starting with a nine-footer at 17.
He rolled in an 11-foot birdie the 18th before birdie putts of six and 10 feet at the first and second.
"It was nice to make a nice putt on 17, nice putt on 18, really good approach on one and then nice putt on two to really get the round rolling and get feeling really comfortable out there," said Harman, who is trying to build momentum heading into the first major of the year, the Masters, at Augusta National next week.
A three-foot birdie at the fifth left Harman four strokes up with four to play and he stuck his tee shot at the par-three seventh within four feet for another birdie.
Harman dropped a shot at his final hole, the par-four ninth, where his tee shot found the left rough among the trees and his 12-foot putt to save par narrowly missed.
But Mitchell had his own troubles coming in. Having started his day with a birdie at the 10th he was one-under through his first nine holes with three birdies and two bogeys.
Still in there
Bogeys at the first and fourth saw him slide further adrift, and after birdies at the fifth and sixth he dropped a shot when he missed the green at the par-three seventh and finished 36 holes at eight-under 136.
"A little up and down ... but all in all I'm still in there," Mitchell said. "I wish I was closer to Brian than I am, but glad to make par on nine so I could stay in the last group."
Overnight leader Sam Ryder was still in the mix despite a two-over 74 that featured four bogeys and two birdies and left him tied for third on seven-under 137.
Ryder said the neck and upper back pain that flared up before the tournament affected him, but mostly, he said "I just didn't play well.
"I kind of got off to a bad start and just didn't really get in a good rhythm," Ryder said. "Yeah, I was feeling it a little bit, but was able to kind of grind through it. All in all, if you told me I was going to be in this position going into Saturday, then I would have taken it I think on Thursday."
He was joined on 137 by Japan's Ryo Hisatsune and England's Matt Wallace, who both shot 67. All are among the players in the field who could earn an invitation to the Masters with a victory on Sunday.