Andy Sullivan carded a six-under par round of 66 on the final day of play to claim his second title in Johannesburg within the space of eight weeks.
The Englishman, who began the day three strokes off overnight leader Wallie Coetsee, made seven birdies and a bogey to finish two shots ahead of five other players, including compatriots Anthony Wall and David Howell, on 17-under par overall to win the event.
Howell and Wall could have forced a playoff had they found two birdies over the final three holes, but their failure to do so signalled victory for Sullivan, who will now claim one of the three Open Championship qualifying spots.
There is some consolation for the duo, however, as they take the other two places for the St Andrew's tournament by virtue of having a higher world ranking than their fellow runners-up.
Sullivan won his maiden European Tour title earlier this year when he came out on top in the South African Open.