Dean Elgar (23 not out) and Faf du Plessis (26 not out) put on an unbeaten third-wicket stand of 53 that steadied the innings after it was rocked by the early loss of Graeme Smith (nine) and Hashim Amla (zero) in successive overs.
The Port Elizabeth pitch did not have the pace and bounce of Pretoria, where Mitchell Johnson ripped through the South African top six in both innings in the first test to finish with 12 wickets as the tourists recorded a crushing 281-run win against the world's number one ranked side.
Johnson still managed to land some body blows, but the Australian pace attack generally bowled a fuller length, hoping to utilise the swing on offer under the overcast conditions.
Having won the toss and elected to bat, Smith was struck on the back leg by Ryan Harris with the score on 10 and the umpire had no hesitation in raising his finger.
In the very next over, Johnson breached the defence of Amla who was also out leg before wicket.
South Africa were teetering at that point, but Elgar, who recorded a pair of ducks on test debut against Australia in Perth in 2012, and Du Plessis showed admirable patience and made it through to lunch.
South Africa made three changes to their starting line-up, handing a debut to 21-year-old Quinton de Kock, who will bat at number seven in the place of all-rounder Ryan McLaren.
Elgar returned the side after Alviro Petersen was ruled out through illness and Wayne Parnell was brought in for spinner Robin Peterson as the home side opted for a four-prong pace attack.
Australia were unchanged from the first test.
- Sports & Recreation
- Dean Elgar
- Hashim Amla
- Graeme Smith
- Mitchell Johnson
- Faf du Plessis
- South Africa