Former Open champion Ben Curtis moved clear at the halfway stage of the Valero Texas Open after Matt Every floundered.
Curtis made use of the calmer early conditions to return his second successive 67 to stand alone at the top of the leaderboard on 10-under.
David Mathis is his closest challenger two strokes behind, after he also shot 67, while Every is a shot further back in a tie for third after floundering in stormy conditions.
Every had dropped two shots before he was forced off after 16 holes due to the weather - and although he returned to the course after a two-hour delay, play was called off due to darkness with the American lining up an 11-foot putt for birdie at the 17th.
Every had set TPC San Antonio alight on Thursday when he went around in a course-record 63, but four bogeys in his opening 12 holes left him plummeting down the leaderboard.
The 28-year-old minimised the damage late with birdies at 14 and 16 to be level with Cameron Tringale, who carded an impressive second-round 65.
But it was Curtis who was deservedly out in front after he became just the fourth player on the PGA Tour this year to go bogey-free through the opening two days.
The 34-year-old American picked up four of his five birdies in his opening seven holes, after starting on the back nine, to go out in 32.
A steady run-in saw him birdie only the par-three third, but it was enough leave him in the box seat to claim a first PGA Tour title in six years.
Curtis won the Open Championship in 2003 at Royal St George's, but he has been winless in America since the 2006 Lumber Classic.
"I'm playing really well," Curtis told the official PGA Tour website.
"I'm doing everything sold. Today started getting tougher with the wind blowing later in the round. I was just trying to keep it simple.
"I hit a lot of close shots and made it pretty easy on myself."
