Keegan Bradley leads the HP Byron Nelson Championship by three shots at halfway after following up his sparkling 60 with a 69.
As expected, the American Ryder Cup star found it much tougher on day two after shooting 10-under in the first round.
But after struggling through his first six holes in one-over on Friday, he found three more birdies - at 7, 10 and 16 - to maintain his three-stroke lead over the field.
It could have have been a four-shot halfway advantage but a bogey at the last meant he signed for a one-under 69 and a 36-hole total of 11-under.
Bradley, who won this event two years ago, is three in front of fellow American Tom Gillis and Korean Sang-Moon Bae.
Gillis, 44, tied his career low round on the PGA Tour with a seven-under 63 in the morning.
He needed just 24 putts although three of those came at his final hole, the ninth, when he missed a nine foot birdie putt for a 61 and then missed the one back.
Bae, meanwhile, fired his second successive 68 to also register eight-under.
Charl Schwartzel, who briefly tied the lead at nine-under after making a birdie to Bradley's bogey at the first hole, is tied fourth after a level par 70.
Tianlang Guan, the 14-year-old from China who wowed the world at Augusta by making the cut before repeating the feat in the Zurich Classic of New Orleans, won't be around for the weekend though.
The teenager shot a second-round 77 on Friday to follow his opening 70.
"Just didn't play my best out there today," Guan said. "I still learned a lot. Still have a lot more to learn."