Padraig Harrington continued his steady negotiation of the New Orleans Classic in Louisiana overnight carding a second round 70 to follow an opening-day 71 putting him five shots off the lead on three under par.
American, Briny Baird birdied the final two holes for a three-under-par 69 to seize the lead going into day three.
Baird sank a 20-foot putt at the last to finish eight under on 136, one stroke better than Australian Peter Lonard and fellow American Jay Williamson.
Lonard surged into the lead after a run of three birdies in four holes but bogeys at the 15th, 17th and 18th meant he had to settle for a 70.
Tied on six-under 138 were holder Nick Watney (67), who took only 21 putts, fellow American Tommy Armour III (68) and Japan's Shigeki Maruyama (68).
South African Tim Clark, who began his round on the back nine, produced a dazzling finish to move into contention. Clark birdied the seventh and eighth before recording a hole-in-one at the 210-yard, par-three ninth for a six-under 66.
He was among a group of 10 players on 139.
Despite his lead, Baird said he did not play particularly well on a course that features firm, sloping greens made trickier by difficult pin placements.
"It didn't feel quite as good as probably the scorecard will make out," said the American, who is chasing his first PGA Tour win. "My swing felt a little loose at times but to get in with a three-under (score), I was very, very pleased."