Arjun Atwal fired a four-under 68 to take sole possession of the second-round lead at the $5.5 million New Orleans Classic on Friday, one shot clear of American J J Henry.
India's Atwal, who has seven international victories but is seeking his first PGA Tour success, had shared the overnight lead with US Masters runner-up Chris DiMarco but mounted a charge on the back nine of the TPC of Louisiana course, carding four birdies and a single bogey to sit on 11-under 133 through 36 holes.
"I got off to a slow start when there was no wind and when the wind started to pick up the conditions became pretty similar to yesterday and that's when I started focusing a little more and started making some putts and made some birdies out there," said Atwal, who lost in a playoff at the BellSouth Classic in early April.
For the second consecutive day Henry turned in a tidy effort on the TPC layout, again carding a five-under 67 with one bogey and six birdies to move within one of the leader at 10-under 134.
After carding a flawless opening round 65 DiMarco had a rollercoaster afternoon mixing three bogeys and a double bogey with four birdies and an eagle to sign for a one-under 71.
DiMarco made his big mistake at the last, a double bogey sending him tumbling out of the lead joining South Africa's Tim Clark three strokes off the pace at eight-under.
Clark had a much less adventurous round, closing with birdies on his final two holes to finish with a three-under 69.
"It leaves a bad taste in your mouth but that's golf. I hit a so-so shot on 18 didn't get away with it and made double," said DiMarco, the world number eight but without a victory since capturing the 2002 Phoenix Open. "I don't know what I was thinking.
"It's not playing easy out there, anytime you can hit under par on this course you've hit a lot of really quality shots.
"But that's the way golf is. To go around this course yesterday with no bogeys I knew there had to be a few in me today."
American Lucas Glover had a flawless day as he finished one shot further back at seven-under 137 after carding a four-under 68, one clear of defending champion Vijay Singh.
Riding the momentum from his victory at last week's Houston Open, Singh had a one-under 71 but was still well in sight of the leader, five shots adrift at six-under 138.
Americans Richard S Johnson and Hank Kuehne were also on 138, one shot clear of Ireland's Padraig Harrington, who had a one-under 71 to leave him level with Japan's Hidemichi Tanaka at five-under 139.