Fichardt, the joint overnight leader, held on for victory, despite dropping three shots in his last five holes to finish the day with a one-under-par 71.
That put him on 16 under for the tournament and earned him his fourth European Tour title, with compatriot Jaco Van Zyl and France’s Gregory Bourdy finishing in a tie for second.
Fichardt had moved four-under-par for the day with birdies at the first, third, seventh and 13th, reaching the turn with a four-shot lead, meaning his late slump did not prove costly.
“I started losing focus,” said Fichardt. “I was four shots ahead and I started taking it for granted.
“I was putting unbelievably and then I missed a short putt at the 14th and thought ‘what’s going on here?’”
Van Zyl tied for the lead with Fichardt going into the final day and was his main challenger over the last 18 holes before a bogey at the last, his third of the round, left him with a 73.
Bourdy had a final round of 70, consecutive birdies at the 14th, 15th and 16th giving him hope of catching Fichardt before a bogey at the 17th all but ended it.
A third South African, Garth Mulroy, was fourth on 13 under following a final-round 67, while England’s Andy Sullivan also enjoyed a decent closing day, shooting 68 to finish on 11 under in a four-way tie for fifth.
After a promising opening two days, Harrogate’s John Parry fell away from the leading pack, following up Saturday’s third round score of 73 with a 74.
Jiyai Shin won the Women’s Australian Open by two shots as teen sensation Lydia Ko faltered in Canberra on Sunday.
A one-under-par 72 in the final round was enough for the South Korean, who finished the four-round tournament at the Royal Canberra Golf Club at 18 under.
World No 1 Yani Tseng made a late charge with a stunning seven under 66, but ended up two shots adrift. New Zealander Ko, 15, could only manage a three-over 76 to finish third at 14-under.