World number one Lee Westwood of England stretched his lead to five strokes on Saturday after three rounds of the Sun City Challenge.
The 37-year-old who replaced American golf icon Tiger Woods at the top five weeks ago had to settle for a one-under 71 at a sun-drenched 7162-metre Gary Player Country Club.
It was his poorest round this week in the five-million-dollar tournament known as the African 'Major', but closest challenger and fellow Englishman Ross Fisher failed to take advantage after starting the round three behind.
Fisher faltered badly after moving within two shots of Westwood with five holes left and missed a birdie putt on the last to end one over on 73 and sharing second place with South African Tim Clark.
After failing to match par in the opening round, Clark has climbed steadily up the leaderboard and did not drop a shot during his third round despite struggling to get distance off the tee.
Larger-than-life Spaniard Miguel Angel Jimenez made too many visits to bunkers on the back nine and a 71 left him alone in third place, six adrift of Westwood.