Adding his national title would be a remarkable fifth European Tour victory of the season for the 24-year-old, who only 11 months ago was at the qualifying school in Spain wondering what was going to come next for him.
Since surviving that ordeal Grace has won the Joburg Open, the Volvo Champions by beating Ernie Els and Retief Goosen in a play-off, the China Open and then last month the Dunhill Links Championship at St Andrews. It included an opening 12 under par 60 at Kingsbarns which equalled the Tour all-time record.
That is not all. On his home circuit the week before flying to Scotland the Pretoria player also lifted the Origins of Golf title.
He is sixth on the European Tour money list and at 39th in the world can start making plans for a US Masters debut at Augusta next April. Not bad for someone who was outside the top 300 a year ago.
"Over the last couple of years I've felt that I've played good golf, but never really got the best out of it," he said. "I never really got where I wanted to be.
"Obviously this year has been a dream year so far and going back home it's going to feel awesome to tee it up in the SA Open."
Last year's Masters champion Charl Schwartzel is also in the field - as is his younger brother Atti - and German Martin Kaymer has made the trip in search of a first solo victory of 2012.
Making the putt that kept the Ryder Cup away from the Americans is a treasured memory, of course, but Kaymer, world number one in April last year, is now ranked 32nd.
For a number of other Europeans the tournament represents the last opportunity to win a card for the 2013 season.
Last year's Challenge Tour winner Tommy Fleetwood tees off 124th on the money list and needing to climb five places.
The 21-year-old Englishman has played 30 events, more than anybody else on the circuit, but has not managed a single top 15 finish.
Scot Craig Lee is 116th on the Order of Merit, but may need one more push as several of those just below him are at the Hong Kong Open, where there is far more prize money on offer.