George Coetzee will head into the fourth and final round of the Investec Cup at the Lost City course in Swaziland with a one-shot lead.
The 27-year-old South African had two bogeys in his two-under-par 70 in the third round on Saturday.
That allowed Trevor Fisher Jnr to close in on the top of the leaderboard, as he carded a five-under-par 67 to move to 10-under-par for the tournament.
"The third round is moving day," SAPA quotes Fisher as saying. "I needed to shoot a five- or six-under.
"I was happy with my performance. I left one or two out there, but the greens were a little slow and I left a few short.
"You don't quite trust your putting stroke on surfaces that are a little bit slow."
Defending champion Jaco van Zyl fired a seven-under-par 65 in the penultimate round to move himself up to eight-under for the tournament.