Grace, listed at No 15 in the latest world rankings, has been installed as the second-favourite for the tournament starting on Thursday.
Leading SA bookmakers Sportingbet have Grace on offer at 9/1.
Sweden's Henrik Stenson, at No 7 the highest-ranked player in the 30-man field, tops the odds at 13/2. Stenson lifted the trophy back in 2008.
Charl Schwartzel, a winner last week at the Alfred Dunhill Championship at Leopard Creek, is on offer at 11/1, followed by last year's winner at Sun City, England's Danny Willett at 12/1.
South African Louis Oosthuizen looks at attractive bet at 16/1...
Round 1 tee-times:
10:10 - Marc Leishman (Australia), Søren Kjeldsen (Denmark), Webb Simpson (United States)
10:21 - Thongchai Jaidee (Thailand), Robert Streb (United States), Scott Piercy (United States)
10:32 - Russell Knox (Scotland), Bernd Wiesberger (Austria), Andy Sullivan (England)
10:43 -Tommy Fleetwood (England), Thomas Aiken (South Africa), Martin Kaymer (Germany)
10:54 - Matthew Fitzpatrick (England), Ross Fisher (England), Keegan Bradley (United States)
11:05 - Shane Lowry (Ireland), Lee Westwood (England), Emiliano Grillo (Argentina)
11:16 -Steven Bowditch (Australia), Byeong Hun An (South Korea), Branden Grace (South Africa)
11:27 -Miguel Angel Jiménez (Spain), Kiradech Aphibarnrat (Thailand), Chris Wood (England)
11:38 - Jaco van Zyl (South Africa), Victor Dubuisson (France), Charl Schwartzel (South Africa)
11:49 -Henrik Stenson (Sweden), Louis Oosthuizen (South Africa), Danny Willett (England)