George Coetzee overhauled compatriots Thomas Aiken and Justin Walters to lead the Joburg Open heading into the home stretch.
The 27 year old South African, who has had 24 top-ten finishes on The European Tour without winning, turned in a four under par 33 at Royal Johannesburg & Kensington Golf Club before holing a six foot birdie effort at the tenth to reach 18 under.
That was one ahead of Aiken and Walters, the two Johannesburg-born players both turning in level par 37s to remain 17 under, with Korea’s Jin Jeong a shot further back in fourth.
Coetzee picked up shots at the first and fourth and found a third birdie of the day when he reached the edge of the sixth green in two and two-putted the par five.
The eighth hole provided a potentially decisive swing as, with Coetzee already having birdied the par five, Walters found trouble with a bunker off the tee and Aiken three-putted to see both run up bogey sixes.
England’s former Walker Cup star Andy Sullivan signed for a seven under par 65 and had to wait to see whether his 15 under clubhouse total would be good enough for a top-three finish and invite to The Open Championship at Royal Liverpool in July.
Coetzee did well to save par from rough at the tenth and a bunker at the 11th, and remained one ahead of Walters with four holes left to play.
Aiken had dropped two back after finding a greenside bunker at the 12th, with Alvaro Quiros joining Sullivan in the clubhouse on 15 under.
Aiken’s chances of a third European Tour title faded dramatically when he missed the 13th green and double bogeyed, and Walters three-putted the same hole to leave Coetzee two clear.
He stretched that advantage to three with a 30 foot putt at the 15th having almost found a hazard from the tee.