Local favorite Jimmy Walker fired a five-under-par 67 to take a one-stroke lead at the halfway stage of the US PGA Tour's Texas Open.
Walker's six-under-par total of 138 put him one in front of overnight leader Charley Hoffman, who posted an even-par 72 and was joined on 139 by Australian Aaron Baddeley, who shot a 71.
It was a further stroke back to another Texan, Jordan Spieth, who carded a 69 and was tied on 140 with Kevin Na, who shot a 68.
Walker, pleased to be playing in front of family and friends, took advantage of improved weather to grab two birdies in his first five holes before his only bogey of the day, at the par-four 17th.
He responded with a birdie at 18, and closed strong with three birdies on the trot at six, seven and eight -- a run that included a 19-foot birdie putt at the par-three seventh.
"I was just kind of around the hole, didn't make anything, and then finally got one to go on six," Walker said.
"I hit a good iron shot, just got it on top of the ridge there on seven and made that putt.
"And that 12-footer I made for birdie on the par-five (the eighth), that was a nice little finish," added Walker, who is seeking his second title of the season after his win in the Sony Open.
The late burst let Walker overtake Hoffman, who was three-under for the day through his first nine holes but had three bogeys coming in to fade.
Baddeley also teed off on 10 and shook off a double-bogey at the par-four 15th, making five birdies and two bogeys the rest of the way.
Walker said a win at TPC San Antonio would be special.
"A win anywhere means a lot," he said. "But being at home, you get to have parents, in-laws, friends, best friends, distant family. It would be cool. It doesn't put anymore pressure on you, I think. If anything you've got a nice support crew out there and you've got good vibes and good mojo — and I believe in all that stuff."
Walker's fellow Texan, Spieth arrived in San Antonio off a dramatic playoff victory in the Valspar Championship in Florida -- his third victory in five months.
For Na, TPC San Antonio will always be linked to the 16 he recorded on the par-four ninth in 2011, but he's hoping to add some new, better memories to his history here.
"I really like this course and played well today," Na said.
Five-time major winner Phil Mickelson, tuning up for the first major of the year at the Masters in a fortnight, fired an even-par 72 to head a group on 142.
He was joined by another former Masters champion in Zach Johnson along with Brendan Steele, Chris Kirk and Billy Horschel.
Source: AFP