The Proteas will face a battle on the final day to save the opening Test against Australia in Durban, going to stumps on 102-4 after being set a target of 421.
Australia have earned a 139-run lead over South Africa after bowling out the lacklustre hosts for 284 runs in their first innings at Kingsmead Stadium on Sunday.
Australia will welcome Josh Inglis back into their squad ahead of the second Test against South Africa as the wicketkeeper-batter continues his recovery from a fractured finger.
Matt Renshaw struck a majestic career-best century before Australia took an early wicket to put the visitors on top after two days of the first Test against the Proteas at Kingsmead.
The Proteas made a good start with the ball on the opening day of the first Test against Australia in Durban, reducing the visitors to 187-6 before bad light brought an early end to the final session.
Proteas spin bowler Simon Harmer expects Australia to bring all their firepower, when the two sides meet in the first of three Test matches in Durban tomorrow.