The 41-year-old South African held his nerve at the last to finish 15-under-par at the rain-affected tournament at the Royal Johannesburg and Kensington Club, edging Stuart Manley of Wales and Englishman Paul Waring.
Fichardt and Waring had been level going into the last round after the tournament was cut to 54-holes because of persistent thunderstorms through the week that left the course waterlogged.
There was another two-hour delay on Sunday before Fichardt set the early pace, along with compatriot Jacques Kruyswijk, whose hopes ended with a double bogey six on the 14th.
Fichardt was two shots ahead going into the last three holes but Waring birdied the 16th and Fichardt carded his only bogey of the round on the 17th.
A birdie from close range on the 18th, however, secured his fifth Tour victory and first since the Africa Open in 2013.
Manley had finished early to take the clubhouse lead with a third successive 67. Waring, looking for a first win in his nine years on the Tour, shot 69 to share second.
The top three all secured spots at the Open at Royal Birkdale in July.
(Reporting by Mark Gleeson in Cape Town; Editing by Toby Davis)
