NEW ORLEANS, April 25, 2013 (AFP) - Barnes matched a course record at TPC Louisiana, where the water-logged course saw players allowed to lift clean and place their balls in the fairway.
The American golfer, who has missed the cut in seven of his last nine starts, had a one-shot lead over former US Open champion Lucas Glover and Boo Weekley.
It was a further stroke back to D.A. Points and Morgan Hoffmann on six-under 66, with South African Ernie Els heading a group of 10 players on 67 that also included Australia Matt Jones and Rickie Fowler.
Another 15 players were tied on 68, a group that included England's Justin Rose and Brian Davis and South African Trevor Immelman.
Chinese 14-year-old schoolboy Guan Tianlang, two weeks after a historic Masters debut as the youngest player at Augusta National, carded an even par 72 that included three bogeys and three birdies.
The teenaged star is playing on a sponsor's exemption.
Barnes is hoping he can be consistent enough to continue the celebratory tone of the week that began with the birth of daughter Natalie.
"I just haven't gotten off to good starts in the first couple of days," Barnes said of his missed cuts this year. "It seems like I'm always just chasing the cut."
He gained early momentum with an eagle at the par-five second hole, where he drained a 12-foot putt.
A birdie at the fourth was balanced by a bogey at six, but Barnes caught fire on the back nine with six birdies coming home. That included a run of four straight birdies starting at the 13th.
Barnes hit all 14 fairways and 15 of 18 greens in regulation.
"At the end of the day, if you give us ball in hand out here we're going to have a chance to go low," he said.
"I knew you could attack the pins this morning because of the soft greens. But if you asked me if I thought I would tie a course record, no, I didn't think that when we went out this morning."
Leading first-round scores on Thursday in the USPGA Tour $6.6 million Zurich Classic of New Orleans (USA unless noted):
64 - Ricky Barnes
65 - Boo Weekley, Lucas Glover
66 - D.A. Points, Morgan Hoffmann
67 - Charlie Beljan, Matt Jones (AUS), Luke Guthrie, Ernie Els (RSA), Rickie Fowler, Billy Horschel, Chris Kirk, Stephen Ames (CAN), Jimmy Walker, Bobby Gates
68 - Matt Every, Harris English, Graham DeLaet (CAN), Jason Kokrak, Kevin Stadler, Jason Bohn, Brian Davis (ENG), Justin Rose (ENG), Gary Woodland, Tommy Gainey, J.J. Henry, Trevor Immelman (RSA), Chad Campbell, Chris DiMarco, James Driscoll