Tjaart van der Walt, Darron Stiles, Bret Waldman and Steve Schneiter share fourth place at minus-4.
Wetterich got off to a great start Thursday at his first hole, the 10th at Meadow Springs Country Club. He roped a 3-wood to 15 feet at the hole to set up eagle, before parring the next seven holes. He collected a birdie at No. 18 for a front-nine 33.
Wetterich made it two in a row with a birdie at No. 1, but he did his back-nine damage a few holes later. He birdied four holes in a row, starting at the fourth, to extend his lead over the field.
'I got to 5-under and expected something bad to happen,' said Wetterich. 'It's been a long time since something like this has happened. Back home, when I have been playing well, I would make bogey or double-bogey and it sets you back.'
Like David Sutherland last week at the Utah Classic, Wetterich is a member of the PGA Tour who is playing in this event in an effort to rehab from injury.
'I still have a long way to go to catch up to where I was,' said Wetterich, who injured his wrist last June and had surgery in January.
Wetterich is playing in only his sixth event on the Buy.com Tour, as he had moved right from the mini-tours to the PGA Tour.
'I think it might have been better if I had played here before making the PGA Tour,' said Wetterich, referring to the Buy.com Tour. 'It was a big change for me going from the mini-tours to the PGA Tour.'
Lee Rinker, Omar Uresti, Charley Hoffman, Vic Wilk, Rob McKelvey, Greg Twiggs and Brian Kamm are knotted in eighth place at 3-under-par 69.
Casey Martin is seven shots off the lead at 1-under par.