Gavin Coles also matched the course record on Friday to move into a tie for third place at 8-under-par 136. He is joined there by Jaxon Brigman and overnight leader Kevin Stadler.
Quinney got going with an 18-foot birdie putt on the par-3 10th, his first. He stumbled to a three-putt bogey at No. 12, but came right back with a birdie at the next. He then dropped in back-to-back birdies from the 16th to make the turn at 3 under for his round.
The 25-year-old, in search of his first Nationwide Tour title, again converted consecutive birdies from the second to get to minus-6. Quinney sank his seventh birdie of the day at the par-4 fifth.
Quinney, an Arizona State alum, birdied the eighth on the Upper Course at Peek 'n Peak Resort, then came right back with a birdie at the ninth, his last, to grab a share of first.
'I was due a round like this,' said Quinney, who has missed three cuts in six events. 'I haven't been in contention on this tour after the first two days in my career. I've played some other tours, but I've been waiting for my chance.'
Painter also started on the 10th tee, but he was steady out of the gate with eight straight pars to start his round. The 39-year-old sank his first birdie at the par-4 18th.
The Australian, who won the 1998 Ozarks Open, made it two in a row when he birdied the first. He came right back with an eagle at the par-5 second.
Painter birdied the sixth and seventh to move into a share of first place. He parred his final two holes to close out a bogey-free round.
'I played good, which is nice to say since it doesn't happen very often,' Painter said. 'I like the lead. I've always enjoyed the challenge of leading. I haven't always done well with it, but I've enjoyed the challenge.'
David McKenzie, Ahmad Bateman, Brad Ott, Matt Peterson and Sonny Skinner share sixth place at 7-under-par 137. Bill Lunde, Jason Caron, Victor Schwamkrug, Joe Daley and Ty Tryon are one stroke further back at minus-6.
The cut line fell at even-par 144 with 73 players advancing to the final two rounds. Among those who missed the cut were Dave Stockton, Jr. (145), D.J. Trahan (146) and Brett Wetterich (148).