Brendan Steele held a three-shot lead when darkness brought an early end to play for a second straight day at the Valero Texas Open.
Only thirteen players - and none near the top of the leaderboard - were still on the course when play was suspended, meaning Steele will begin the weekend with a healthy advantage despite some struggles in his second round.
Steele began the day still midway through his first round, which he eventually finished in 64 for a one-shot lead over Patrick Reed.
But although he would build his lead, things did not go so smoothly for the American - whose only previous PGA Tour win came here in 2011 - second time around as six birdies were tarnished with dropped shots at the fifth and ninth holes, and a double bogey on the par-four 15th, leaving him on 10 under for the tournament.
"I definitely feel comfortably here," Steele said on the PGA Tour website. "Other than the win I've had a couple of other good results here and it's good to come back somewhere you feel good at.
"There's so much trouble down either side of every hole, if you drive it well you'll be in pretty good shape and that's normally a good part of my game so I try to lean on that."
However, Steele said he had been thrown off his game by some unusual pin placements on the day.
"There were definitely a couple I'd never seen before. The one on five, we saw the dot this morning and the dot kind of freaked me out, I didn't know you could put a pin back there and it ended up affecting my wedge shot and making bogey because of it. There were a couple I hadn't seen before and I wasn't really comfortable with."
Steele's struggles seemed to open the door for Charley Hoffman - who began two shots back - to make a move but, despite an eagle on the par-five second, he had three bogeys on the front nine in a round of 71 and slipped back into a share of second at seven under alongside Scott Langley and Stuart Appleby.
Langley had an eagle on the par-five 14th in a round of 68, while Appleby was able to survive a triple bogey on the 10th and dropped shots on the 15th and 18th thanks to seven birdies in his round of 70.
Reed fell into a seven-way tie for fifth place after a second round of 73 which featured five birdies, four bogies and a double bogey on the par-four 12th.
Padraig Harrington will make the the cut for the weekend after his second round 71 left him on 3-under and three shots clear of the projected cut of par.