Adams, chasing his first Nationwide Tour win, collected nine birdies and a lone bogey on the Hillcrest course to match a career-best score.
He grabbed a one-stroke lead over Jonathan Kaye, who bogeyed his last hole to shoot a 7-under 64.
Patrick Sheehan and J.J. Killeen shared third place at 6-under 65, with Justin Bolli, Skip Kendall and Martin Piller another shot further back at 66.
The long-hitting Adams dropped his only shot of the round on No. 1 – but he could have made much worse than a bogey. Standing with one foot in the sand, he knocked his second shot at the par-4 hole into a tree branch, then put his third into a greenside bunker.
Adams blasted out to 20 feet and rolled in the putt to escape his first hole with a bogey.
'I don't know if there's anything such as a good bogey. But I'll gladly take that,' he said. 'Looking back on it, considering the lies I had in the rough and the bunker, I was glad to make five.'
Adams recovered to make five birdies on the front nine, including two in a row after his opening bogey. He also made three consecutive birdies between the fifth and seventh holes.
Giving credit to his short game – particularly his wedge play and his putting – Adams made four more birdies on the back nine to take the early lead.
His advantage stood up as Kaye, tied for the lead after 17 holes, missed a 3-foot par putt on the 18th hole in an afternoon group and ended a shot behind.
'I just putted well, that's the main thing,' Adams said of taking the lead. 'I hit some good shots but I just made the putts. That's the difference in anybody's round out here. Everybody hits it about the same, it's just who makes the putts.'
Sam Saunders, the grandson of Arnold Palmer, made his Nationwide Tour debut Thursday shooting even-par 71. Rickie Fowler, who helped the U.S.win the Walker Cup last week, shot 2-over 73 in his professional debut.