Australia batted through to the end of day three without losing a wicket but they remain a mammoth 591 runs behind the total set by South Africa in the third Test in Perth.
South Africa set the hosts a world-record chase of 632 thanks to big centuries from Hashim Amla and AB de Villiers.
Australia's reply has reached 40 without loss, with David Warner on 29 and Ed Cowan nine not out from 13 overs.
The tourists have two days to bowl out Australia to claim a series draw after losing the first Test and saving a draw in the second.
