Richard Sterne and Trevor Fisher Junior continued to head the field on a birdie-packed third morning of the Joburg Open.
The two overnight leaders each picked up a shot on the first to move to 16 under for the tournament.
George Coetzee remained three adrift, having also started with a birdie, while Garth Mulroy, the pick of the morning starters, was in the clubhouse at 12 under.
Runner-up here in 2011, Mulroy picked up four birdies on each nine en route to a 65, with his only dropped shot coming at the par four tenth.
Tom Lewis was another to make good progress with a front nine 32 that featured an eagle at eight. However, after another birdie at the tenth he then bogeyed the 12th to slip back to 11 under, the same score as Charl Schwartzel, a two time winner of this event.
Danie van Tonder, Paul Waring and Justin Walters all went round in 67 to reach 10 under, although the latter may rue a missed opportunity after turning in 31 with the aid of an opening eagle and four birdies.