Louis Oosthuizen will take a one shot lead into the final round as he looks to make it back to back wins at the South African Open hosted by the City of Johannesburg.
The tournament host claimed an emotional victory last season as he won his home open for the first time and a third round 64 at Randpark Golf Club put him on track to make it two in a row.
The 2010 Champion Golfer of the Year will head into day four at 15 under, one shot clear of England's Marcus Armitage, as he looks to become the first player to successfully defend this title since countryman and fellow Major Champion Trevor Immelman 16 years ago.
South African Jaco Ahlers was at 13 under, a shot clear of countrymen Jacques Blaauw, Branden Grace, Martin Rohwer, amateur Jayden Trey Schaper and 2015 champion Andy Sullivan.
Armitage had held a four shot lead at one point as he set the clubhouse target but Oosthuizen produced some brilliant par saves and seven birdies in a wonderful bogey free display.
The 37-year-old could claim a tenth European Tour victory on Sunday as he celebrates being one of just ten players to have spent the entirety of the 2010s in the top 100 on the Official World Golf Ranking.
"Getting my name on the trophy again would really mean the world to me," he said. "Defending it and being the host for the week would make it extra special.
"It was good, it was solid. I gave myself lots of opportunities for birdies and the putter was a lot better."
Oosthuizen was in a share of second as he holed a 15 footer on the second, made another birdie on the third, and completed his hat-trick with the help of a nice chip on the fourth.
A seven foot putt on the ninth then saw him turn in 31 but at that point he was still two behind the surging Armitage.
The 32-year-old birdied the second and holed his second shot at the par four third with a wedge before putting an approach to six feet at the sixth for another gain.
A very long putt at the seventh put him into double figures and when a birdie at the ninth saw him turn in 29, he had a share of the lead.
He hit the front on his own with a birdie on the par five 12th and a putt from the fringe on the 14th handed him a second eagle of the day and a three shot lead.
His tee shot at the par three 17th left him 15 feet and he led by four before his second left him in a treacherous position on the last and he closed with a bogey.
Oosthuizen hit a stunning shot out of the rough on the 11th for a birdie and another gain on the par five next had him in a share.
He then sandwiched a birdie on the par five 14th with remarkable par escapes on the 13th and 16th to lead the way.
Armitage is looking for a first European Tour title after regaining his card at the Qualifying School and his brilliant 62 was a remarkable 21 shots better than his closing effort at last month's Alfred Dunhill Championship.
"That's why we play golf, for them days like today," he said. "It was just magic. I haven't been in the lead for a long time so it's good to be able to finish it off, have a good round and know that you've still got it."
Ahlers made six birdies and three bogeys in a round of 68, one better than 18-year-old Schaper who bounced back from a double bogey at the second with an eagle and two birdies.
Englishman Sullivan, Blaauw and Grace all carded rounds of 67, with Rohwer signing for a 64.
George Coetzee, Thriston Lawrence, Min Woo Lee, JC Ritchie and Jack Senior were all at 11 under.
