Spencer Levin, Tyler Aldridge, Andres Gonzales, Brad Fritsch and Keoke Cotner were tied for third place at 5-under 66.
Josh Broadaway, Ben Bates, Brad Weesner, Jeff Gallagher, Kevin Larsen, Ian Leggatt, Scott Gutschewski and Dustin Bray were another shot further back at four-under 67.
Overall, there were 61 players separated by just five shots at the top of the leaderboard after a steamy first day at TPC Wakefield Plantation when the heat index reached 105 degrees.
Owen, playing in the second morning tee time off No. 1, was just even-par after nine holes. But he made a run on the back nine, beginning with a tap-in birdie at the 10th and then three birdies in a row ending at the 14th.
The 36-year-old Englishman, who is seeking his first Nationwide Tour win, finished off his 65 with back-to-back birdies on the last two holes to take the early clubhouse lead.
'This is probably the best I've played all year,' said Owen, who made more than $3 million playing on the PGA TOUR the past three seasons.
'I've been working hard all year. I believe I belong [on the PGA TOUR] and I've proven I can compete out there. I'm here for a reason and I have to work hard to get back.'
Quinn, a 43-year-old two-time Nationwide Tour winner, played the back nine first in an early-afternoon group.
He collected four birdies in a seven-hole stretch beginning at the 12th, then finished his bogey-free round with birdies at the sixth and eighth holes to tie Owen for the lead.
Quinn, whose last Nationwide Tour win came in 2000, said he was fortunate to take advantage of the easy birdie opportunities he earned on Thursday.
'I hope I can do the same tomorrow,' he said. 'The heat was draining today and that made it difficult. Normally I would practice after my round but today I told my caddie to pull the car up and get the A/C cranking.'