David Lipsky fired a 66 to take a one-shot lead on day two of the Alfred Dunhill Championship but he had four Scotsmen breathing down his neck at Leopard Creek Country Club.
The American registered four birdies and an eagle to get to eight under but Scottish pair Scott Jamieson and Marc Warren were just a shot back, with compatriots David Drysdale and Doug McGuigan a further shot back at six under.
Jamieson and Drysdale both came close to losing their places on the European Tour last season, while Warren lost his and had to go back to the Qualifying School, with all three men looking to bounce back in the wraparound 2019 season.
McGuigan is a veteran of the South African Sunshine Tour and the 48-year-old rolled back the years with seven birdies on the back nine as he made nine consecutive one-putts.
Irish duo Gavin Moynihan and Neil O'Briain both finished over par and will not be around for the weekend action.
Moynihan bounced back from a disappointing opening round 78 to post a two-under-par 70, however, the Dubliner still missed the cut by two shots.
O'Briain shot 75 in his second round, coupled with his four-over 76 on Thursday to finish on seven over par.
Starting on the 10th, Lipsky made a birdie on the 11th and an eagle on the 13th before adding further gains on the 16th, second and third.
"I played really well," he told europeantour.com. "I actually didn't hit it that great today but my putting and chipping was amazing. I got the job done and tied it up and I'm looking forward to the weekend."
Jamieson made five birdies in six holes from the 13th in a 66, while Drysdale recorded four birdies and a bogey in a 69.
A holed bunker-shot on the eighth was the highlight of Warren's 67 and he was delighted to be playing well again after his disappointing 2018 season.
"I think I learned a lot that week (at Qualifying School)," he said. "I thought it was going to be a long week so I kind of surprised myself.
"I felt like I just played golf, purely. I just played the shots I felt I could play. I felt like I was playing golf again as opposed to playing golf swing so I'm just trying to take that approach into the new season."
England's Oliver Wilson and defending champion Brandon Stone were in the group at five under.