Gibson is joined atop the leaderboard by Mike Standly (67) and first-round leader Nick Watney (70). Craig Lile (70) and Ben Bates are one stroke further back at minus-6.
Gibson got started on the back nine of Diamante Golf Club as did his fellow leaders. He rolled in his first birdie at the par-4 10th. The two-time winner on the Nationwide Tour drained his second birdie at the 16th.
The 39-year-old made it two straight when he sank a birdie at the par-4 17th. Gibson closed his opening nine by making his third straight birdie at the last.
Gibson picked up his fifth birdie of the day at the par-3 fourth. He gained a share of the lead when he birdied the par-5 eighth.
'You can't have greens better than this,' Gibson said. 'They hold, they're firm and they're fast. Still, there is so much golf left to be played and you can have a bad round just as fast as you can have a good round. It's a momentum golf course.'
Standly had a quiet opening nine as the only scoring he did was on the par-4 14th where he dropped a shot to fall to minus-1.
Around the turn, Standly rolled off three straight birdies from the third. That string was ended when he eagled the par-4 sixth. Standly birdied the eighth to grab a share of first.
'I was struggling. I was missing greens, chipping up and making putts and trying to keep it in play,' said Standly. 'I was just trying to keep it in play. I was struggling but then something clicked when I made a birdie on the third.'
Watney opened with a birdie on No. 10, his first. He stumbled to a bogey at the 12th though. He moved back into red figures with a birdie on the 16th to get to 6 under.
On the front side, Watney birdied the third before stumbling to a bogey at the next. He erased that mistake with a birdie at the fifth and parred in to remain in a share of the lead.
'I thought the pins were in some tougher spots today,' said Watney, a tour rookie. 'I didn't make as many putts and I'd like to say to I left a few shots out there, but I think you can say that about almost any round.
'It's nice to be in the lead, but we're only halfway there. It's to validate the fact that maybe I can play with these guys, but in the big picture it doesn't mean much, there's still a lot of golf left to play.'
John Elliott fired a 6-under 66 of his own to climb to 5-under-par 139. He shares sixth place with Bill Lunde (71), Gary Hallberg (69) and James Driscoll (70). Vaughn Taylor, the 2003 Knoxville Open winner, carded a 1-under 71 and is one stroke back at 4-under-par 140.
The cut line fell at 2-over-par 146 with 66 players advancing to the final two rounds. Among those who missed the cut were Hunter Haas (147), Todd Barranger (147), Doug Garwood (148) and Gavin Coles (150).