Coetzee has been a member at Pretoria Country Club since taking up the sport and put his local knowledge to good use to card a third round of 68 and reach 14 under par.
England’s Sam Horsfield and Finland’s Mikko Korhonen are Coetzee’s nearest challengers on 12 under, Horsfield surging through the field with a flawless 64 – the lowest round of the day – and Korhonen returning a 69.
Scotland’s Scott Jamieson is four shots off the lead after a third round of 67, with Felipe Aguilar, Thomas Aiken and Erik van Rooyen alongside Jamieson on 10 under. The quartet are tied for fourth place.
Jamieson has showed admirable consistency this week, and his record of 67-69-67 leaves him with a fighting chance going into the final day.
Fellow Scot Connor Syme was also in impressive form yesterday with a round of 68, leaving him on seven under, seven shots behind Coetzee.
“I’m happy with a two-shot lead,” Coetzee told europeantour.com, despite a bogey on the 18th after his drive finished behind a tree. “I’m looking forward to tomorrow. Playing in front of a home crowd is what it’s all about. I hope I can do something special in front of all the guys tomorrow.
“I shouldn’t actually think of anything tomorrow – just try and play some good golf. It will be hard to take the win out of the picture, but I’ll try my best to just go out and play some good golf.”
Horsfield, who came through all three stages of the European Tour’s qualifying school and won the final by eight shots, held the outright lead after birdies on the first four holes and further gains on the ninth, 11th and 12th before settling for six straight pars to finish.
“When I was seven under through 12 I just tried to stay in my zone,” the 21-year-old said. “I was playing with Matt Baldwin and I know him pretty well. We played together at Q-School and we just had fun out there.
“I think everyone just wants to get themselves into contention and I’ve done that, so tomorrow’s going to be a fun day. I had a good week at Q-School, so when I get into contention, I can look back on something like that.”
In Australia, England’s Meghan MacLaren will head into the final round of the Women’s NSW Open with a two-shot lead after a stunning 65 yesterday.
MacLaren fired five birdies on the front nine before delivering a birdie-birdie-par finish to get to ten under par and break up a crowded leaderboard.
She told the Ladies European Tour’s website: “I’m delighted. I played well yesterday and the day before in wind, but to convert it into a score that really sets the mark for tomorrow feels great.”
Speaking of her previous success on the Access Series, she said the victory will help her going into day four. “If you know you can get over the line, it makes a massive difference,” she added.
Norway’s Marita Engzelius was alone in second place on eight under after shooting a third-round 68 at Coffs Harbour Golf Club.
Home hope Rebecca Artis, Spain’s Silvia Banon and Thailand’s Pannarat Thanapolboonyaras were three shots further back in a tie for third place.