Dickinson, a 30-year-old Monday qualifier, made eight birdies to stand atop a field that includes 35 previous winners on the PGA TOUR.
'It was one of those days where I basically made everything I looked at,' he said. 'I played a practice round on Tuesday and I couldn't really find any birdie holes. But somehow I found eight of them today.'
John Huston, a seven-time winner on the PGA TOUR, had a 6-under 66 and shared second place with Dave Rummells, while Jason Enloe and Scott Parell were a shot further back in fourth place.
Dickinson hit 11-of-14 fairways and 15 greens in regulation and made birdies on four of his final six holes.
Five of his birdies Thursday came on putts inside 10 feet -- he needed just 25 putts for the entire round -- but the highlight of his day came on a much longer roll.
Dickinson capped his round with a 30-foot birdie putt on No. 9 -- his last hole.
'I haven't played this well in a while,' he said. 'I don't remember when I've rolled it this well. Hopefully I'll keep it going the rest of the week.'
A former University of Alabama-Birmingham standout, Dickinson gave up golf last spring and worked temporarily as an insurance salesman before getting back to golf on the Hooters Tour.
'I was at a crossroads last year where I almost gave the game up for good,' he said.
Now, he's leading at a course -- the Davis Love III-designed Kinderlou Forest -- that measures 7,781 yards, the longest course ever to host a PGA TOUR- sanctioned event.
'There is not much rough out here, so there isn't as much of a premium on straight driving,' Dickinson said. 'Obviously length helps. I'm not a long hitter so I'll rely on long irons chasing up to the hole.'