The hometown trio was joined atop the leader board at 16-under 200 by Mark Tullo of Chile, who finished Saturday's third round with a 67.
Fichardt, who won the African Open two weeks ago, birdied the final three holes to complete a round unsullied by bogeys. Coetzee battled to a 68 and Van Der Walt birdied the 18th to close out his 67.
Louis De Jager, who also hails from South Africa, shot 65 for the second consecutive round and moved up to fifth place. American Peter Uihlein scored a 68 and was 14-under for the tourney.
The second round, which had been suspended Friday due to lightning, was completed before the field hit the links for Round 3.