American John Huston returned an error-free six-under-par 66 to grab a one-shot lead over South Korea's KJ Choi after the second round of the Greensboro Classic in North Carolina.
Huston, who began the day at Forest Oaks Country Club four behind overnight leader Charles Warren, has carded only one bogey on his way to a 12-under total of 132.
"I've played pretty solid this week. I've made a lot of putts and my short game's been pretty good," Huston told reporters.
"I haven't had to count too many bogeys. I think that's been the key.
"Other than one putt, I made just about every putt that I should have made today," added Huston, a seven-times winner on the PGA Tour.
Choi mixed four birdies with one bogey in a 69 for 133.
"This morning it was cold," Choi said through an interpreter. "I mainly was focusing on one hole at a time, you know, trying to extend my score hole by hole.
"There was some wind but after nine holes it seemed to die down a little and I managed to play well."
Britain's Justin Rose tied the day's best round, a seven-under 65 putting him joint third on ten-under 134 with American DJ Trahan.
South African Tim Clark, 2003 champion Shigeki Maruyama of Japan and Americans John Rollins and Brian Gay were on 135.
Warren, who opened with a course record-equalling 62, slipped back into the pack with a two-over 74, joining Swedes Carl Pettersson and Daniel Chopra and Americans Tim Herron and Jason Bohn on 136.
Spain's Sergio Garcia, the world number six, stayed in contention with a 69 for 138.
Defending champion Brent Geiberger registered a 69 for 142 to miss the cut by a single stroke.
