John Mallinger is alone in second place after a 6-under-par 66. Boo Weekley is alone in third, one stroke further back at minus-5.
Jason Buha, Steve Schneiter, Matt Hendrix, Craig Kanada, Jason Allred, Scott Parel and Scott Weatherly share fourth place at 4-under-par 68 at Pete Dye Golf Club.
Long started on the back nine Thursday. After five straight pars, Long drained a 25-foot eagle putt on the 15th, and came right back with an 8-foot birdie putt at the next.
The New Zealander, who turns 38 on Sunday, made the turn at minus-3 as he parred the 17th and 18th. Long dropped his approach 8 feet from the hole on No. 1 and sank that birdie try.
Long knocked in a 6-foot birdie effort on three, but three-putted for bogey at the next to slip back to 4 under.
He quickly atoned for that error with a 12-foot birdie putt on five. Long would go on to birdie his final four holes as well. At six, Long made a 4-footer for birdie, then a 15-footer at the next.
Long two-putted for birdie at eight and closed with a 12-foot birdie putt on nine to end three clear of the field.
'That (second) nine was something crazy,' said Long, a two-time winner on the Nationwide Tour. 'Making five birdies in a row to finish the round was fantastic. I made birdie on No. 5 after the bogey on four and it snowballed from there.'
Mallinger converted 12-foot birdie putts on one and four. In between, he tripped to a bogey on the second. Mallinger birdied five from 10 feet out, then made back-to-back 20-foot birdie putts at six and seven to move to minus-4.
The 26-year-old two-putted for birdie at the eighth, then kicked in a 6-footer for birdie on nine to make the turn at minus-6.
Mallinger bogeyed the 10th, but got that stroke back with a birdie on 14. He moved to minus-7 with a birdie on 17, but gave that shot right back with a bogey at the last.
'I played really solid. I got hot as I birdied the last six on the front nine for a 30,' Mallinger said. 'I missed a couple of short ones on the back nine, but other than that I can't complain.'
Ricky Barnes, the 2002 U.S. Amateur champion, and Michael Putnam, a member of the 2005 U.S. Walker Cup team, are among 13 players tied for 11th place at 3-under-par 69.