Johnson stands at 11-under 203 for a one-shot lead over Tommy Gainey, a former and current competitor on the GOLF CHANNEL series 'The Big Break' who continued his surprising run this weekend with a 2-under 69 in the third round.
Gainey, making his first-ever start on the Nationwide Tour, held a share of the second round lead.
'This is a very good feeling,' said Gainey, who was at 10-under 204. 'I've finally got a chance to play and I'm trying to take advantage of it. I'm focused on what I need to do -- and that's win this tournament. I'm playing to win.'
David Mathis fired the round of the tournament Saturday, a 10-under 62, to climb from a tie for 70th place overnight into a share of third alongside first-round leader David Hearn (68) and Peter Tomasulo (69).
That group was at 9-under 205.
Johnson hit 10 of 14 fairways and 13 greens in regulation and made six birdies with two bogeys. He closed with back-to-back birdies at the 17th and 18th to claim the lead.
Sunday, he will be gunning for his third Nationwide Tour win and first since 2000.
'I played solid,' he said. 'I started to change my swing at the end of last year and it's starting to come around. It's a work in progress...but I'm comfortable enough to play with the changes now.'
Gainey found just nine fairways and 13 greens in regulation, collecting six birdies along the way. He was sidetracked by a double-bogey at No. 3 and two additional bogeys, including one at the 17th.
'Today was not one of my better ball-striking rounds,' said Gainey, who was known as 'Two Gloves' on 'The Big Break IV: USA vs. Europe.'
'I made mistakes and chose the wrong clubs sometimes,' he continued. 'So to be 2 under with the way I played is good.'
Johnson played Saturday's round at Cliffs Valley, one of three host courses this week -- and the one that will host Sunday's final round. Gainey shot his 69 at Keowee Vineyards.
Only one player among the top 19 on the leaderboard (Tomasulo) played his third round at Walnut Cove, the other host course.
After three long rounds with an especially large field, the cut line fell at 1-under 213 Saturday with just 60 players moving on to the weekend.
Gary Player, the 71-year-old Hall of Famer from South Africa, ended his fourth straight appearance in this event with a 76 at Cliffs Valley. He finished in second-to-last place.
Gainey, a Bishopville, S.C. resident will face Ashley Gomes in the finale of the GOLF CHANNELs The Big Break VII: Reunion Tuesday at 10 p.m. ET.