Fichardt's closing one-under-par 71 handed him victory over France's Gregory Bourdy (70) and another South African, Jaco Van Zyl (73), who finished tied-second on 14-under.
Fichardt had started the day tied at the top of the leaderboard with Van Zyl before the 37-year-old pulled four shots clear on the front nine.
However three bogies on the 14th, 16th and 17th made for a nervy finish in windy conditions before he claimed a fourth title on the European Tour.
"I started losing focus," he told reporters.
"I was four shots ahead and I started taking it for granted. I was putting unbelievably and then missed a short putt at the 14th and thought 'what's going on here'."
Fichardt, who will move into the world's top 100 from his current position of 146, became the second successive South African winner on the tour following Richard Sterne's victory at the Joburg Open last weekend.
Compatriot Garth Mulroy (67) fired the joint-best round of the day to finish alone in fourth place on 13-under.