Weibring was at 13-under 197 overall and seeking his first win on the Nationwide Tour.
Darron Stiles, the 2006 champion, had a 2-under 68 and was one shot off Weibring's lead at 12-under 198, with Kris Blanks (66) three strokes further back at 9-under 201.
Daniel Summerhays (65), David Lutterus (68), Kris Cox (70), David Morland IV (70) and Rich Morris (72) were at 8-under 202 and the only other players within five shots of the lead.
Weibring began the day in third place, one shot off the 36-hole lead shared by Stiles and Morris.
'I kind of had the feeling just by the people around us that it was the three of us at the top,' said Weibring. 'I guess we were all in or near the lead, but I can't worry about what they do or what anybody else does.'
Focusing on his own game, Weibring got off to a steady start with three consecutive pars and a birdie at the par-3 fourth. He dropped a shot with a bogey at the fifth, but got it back on the next hole with a birdie at the sixth.
Making the turn at 10 under, Weibring went on to eagle the par-5 11th and birdie back-to-back holes from the 13th. He stumbled to a bogey at the 17th, while Stiles made an 8-foot birdie putt there to trim the lead to just one shot.
Weibring, a 28-year-old Texan who ranks 92nd on the money list, will be seeking his first career Nationwide Tour victory on Sunday. His bogeys on Saturday were the first two shots he has dropped through 54 holes.
'I played really, really solid today,' said Weibring, who needed just 26 putts in the third round. 'I just tried to worry about my own game and not focus on anybody else. I putted good, hit the ball good and made some good up-and- downs. I can't complain.'
Stiles called his 5-iron to eight feet at the 17th hole -- setting up birdie -- the highlight of his afternoon. But his 68 on Saturday was five shots worse than the 63 that gained him a share of the overnight lead.
'I played steady and the mistakes I made I got myself out of by some good chips and some good putts,' said Stiles. 'Yesterday I hit the ball pretty close and today I had only a handful of shots inside of 15 feet. I didn't play bad, I just didn't get it going.'