Martin Kaymer rolled in a tricky 10-foot par putt on the last to shoot a 2-under 70 and hold a one-stroke lead on Saturday heading into the final round of the Nedbank Golf Challenge.
Europe's Ryder Cup star made three birdies and a bogey on an overcast and breezy day, ensuring low scores were out of reach at the Gary Player Country Club.
Louis Oosthuizen (69) is next at 4 under, while fellow South African Charl Schwartzel (70) is two back from Kaymer.
Oosthuizen and Schwartzel are lined up for a final-day push for a first home win at Sun City since 2007.
Two-time defending champion Lee Westwood made a late move for an unprecedented third straight Nedbank title by shooting a 70 to sit three off the lead.