The South African looked like a sure bet for his fourth career European Tour title after he sank a 20-foot birdie putt at the 13th to put himself four strokes clear of third-round co-leader Jaco Van Zyl at minus-19.
But he stumbled to bogeys on the 14th, 16th and 17th holes, giving Van Zyl an opening.
Fichardt claimed the crown when Van Zyl bogeyed the 18th, ending at 16-under-par 272.
Van Zyl registered a 1-over 73, finishing in a second-place tie with Gregory Bourdy (70) two shots back at 14-under.
Sole possession of fourth place at minus-13 went to Garth Mulroy (5-under 67), while Andy Sullivan (68), Desvonde Botes (70), Mark Tullo (71) and Tjaart van der Walt (71) shared fifth place at 11-under.