Louis Oosthuizen picked up two shots in his first ten holes to open up a one-shot lead on day three of the South African Open hosted by the City of Johannesburg.
The Major Champion led after day one but had to battle to a 70 on Friday and while he was not at his brilliant best at Randpark Golf Club, he moved to 12 under and was one ahead of Matt Wallace.
Zambian Madalitso Muthiya, overnight leader Charl Schwartzel and Zimbabwe's Mark Williams were then at ten under.
There was a 20-minute delay due to the threat of storms but the sun was out by the time the final group hit away and plenty of early birdies to be had.
Oosthuizen holed a long putt for birdie on the opening hole and that soon had him in a share of the lead as Schwartzel went left off the tee and missed a short putt for par to drop to 11 under.
Muthiya was just off the green with his second into the second but took the putter out and holed a very long right-to-lefter to hit the front on his own.
A Schwartzel three-putt on the third then dropped him to ten under and he was joined there by Wallace, who played the par five fourth in textbook fashion after holing an eight-footer at the third.
Williams was playing alongside Wallace and he also took advantage of the par five, a feat repeated by Oosthuizen in the group behind.
The 2010 Open Champion dropped a shot on the next, however, allowing Muthiya to move two ahead when he got on the green in two.
The 35 year old then had a rotten stroke of luck on the par-three fifth, missing the green and hitting a poor chip before having a double-hit when trying to play a fairway wood from the fringe.
The resulting double-bogey dropped him to 11 under and Oosthuizen moved ahead after a beautiful pitch into the sixth.
Williams missed the green at the par-three eighth and despite being faced with more fringe than green, he elected to putt and holed it - moving to 11 under.
He was not there for long after three-putting the ninth and Wallace replaced him in a share of second after almost driving the par four.
A three-putt on the eighth dropped Muthiya to ten under and he had gone from two ahead to two behind in the space of four holes.
Branden Grace, Kurt Katayama and Jbe Kruger were at nine under, a shot clear of Zander Lombard.
