South African was one shot behind compatriot Branden Grace ( Callaway Golf ) with two holes to play .
South African birdied them both to card a closing 68 and win by one shot on 12 under par .
South African was one shot behind compatriot Branden Grace ( Callaway Golf ) with two holes to play , but birdied them both to card a closing 68 and win by one shot on 12 under par .