Scott Jamieson fired a brilliant bogey-free 67 to take a one-shot lead into the final round of the Nedbank Golf Challenge hosted by Gary Player.
The Scotsman's only previous European Tour win came in South Africa at the 2013 Nelson Mandela Championship presented by ISPS HANDA but he will be going in search of Rolex Series glory on Sunday.
He made five birdies in round three to move to eight under and lead the way from Victor Dubuisson at Gary Player Country Club.
Jamieson can expect a strong challenge from the Frenchman who has a stunning record at this time of year with two wins at the Turkish Airlines Open, two top fives here and three top fives at the DP World Tour Championship, Dubai in November and December since 2013.
Home favourite Branden Grace was then at five under alongside two-time Major Championship winner Martin Kaymer, with Italian Francesco Molinari and South African Haydn Porteous two shots further back.
Race to Dubai Rankings presented by Rolex leader Tommy Fleetwood was in the group at two under after a 67 as he looks to increase his lead over Justin Rose by as much as possible heading into next week's season finale.
Fleetwood would be crowned Europe's Number One with a victory here in Sun City.
Jamieson made a birdie on the par five second but overnight leader Dubuisson restored the three-shot gap quickly, hitting a stunning recovery to five feet after sending his tee-shot well right off the first tee.
The 33 year old hit a smart tee-shot into the par three fourth and holed a 20-footer to get to five under and when Dubuisson missed the green on the third and failed to get up and down from the rough, the lead was down to one.
Dubuisson hit an excellent tee-shot into the fourth to get back to seven under but Jamieson took advantage of the par five ninth and when the leader three-putted the eighth, top spot was shared.
It would be the biggest moment of my career, I'll be well aware of that tomorrow. I've got to see if I can step up to the challenge - Scott Jamieson
The 27 year old made the most of the par five tenth to edge back ahead but put his tee-shot into the trees on the 11th and a long putt from Jamieson on the 13th had him in the lead on his own.
Jamieson got to the side of the par five 14th in two and down in just as many blows to double his advantage but Dubuisson made a gain on the same hole to cut the gap.
"It was much the same tee-to-green probably as the other few days," said Jamieson. "Just the putter was a little hotter today. I got rid of those three-putts I had earlier on in the round yesterday.
"It's exciting. I'm in a good position, tomorrow will be a new challenge. Still an awful long way to go but if I can do what I did today, I'll be in with a good shout.
"It would be the biggest moment of my career, I'll be well aware of that tomorrow. I've got to see if I can step up to the challenge."
The conditions had got the better of Grace on day two as he fired a 75 and when he bogeyed the fifth, it looked like he could already be too far back. But he does not have seven European Tour titles for no reason and made birdies on the sixth, eighth, tenth and 11th to fly up the leaderboard.
Another gain followed on the 14th and a spectacular chip-in on the next had the home crowd excited before he got in trouble off the tee and dropped a shot on the last.
Kaymer holed a long putt on the second, made another birdie on the fifth and then chipped-in on the eighth to cancel out a bogey on the seventh.
The German took advantage of the tenth and then put an approach to tap-in range on the 15th before a poor chip brought a bogey on the penultimate hole.
Molinari was bogey-free as he recorded the lowest round of the week with a 65, while Porteous had an eagle, five birdies and two bogeys in a 67.
England's Ross Fisher and Lee Westwood were at two under alongside countryman Fleetwood, with South African Major winners Louis Oosthuizen and Charl Schwartzel, Scot David Drysdale and Frenchman Matthieu Pavon also six shots off the lead.