Reeling from a ball-tampering scandal, Australia struggled on the field as South Africa's lead neared 400 on the fourth morning of the third Test at Newlands today.
South Africa had reached 333 for seven at lunch, an overall lead of 389, after adding 95 runs to their overnight 238 for five.
Although AB de Villiers fell to the second new ball for 68, Quinton de Kock (65) and Vernon Philander (39 not out) scored freely in a sixth wicket stand of 55 off 67 balls.
A muted chorus of boos greeted Australia when stand-in captain Tim Paine led the team out at the start of play after regular captain Steve Smith and vice-captain David Warner were stood down following Saturday's ball-tampering revelations.