Australia began the second Test against South Africa on the front foot by snatching two early wickets in the morning session of day one at Port Elizabeth.
The hosts won the toss and elected to bat, with Graeme Smith and Dean Elgar taking to the crease in blustery conditions.
There was a lack of movement for South Africa having failed to get a run on the board from the first two overs, but Smith soon got off the mark with a boundary.
However, it wasn't long before the Aussies found the breakthrough with Ryan Harris, who dismissed Smith for an lbw on nine runs from 19 deliveries.
The hosts sat on 10-1 when their opening batsman was sent packing, but they were soon dealt a fresh blow when Hashim Amla was hit for a duck by Mitchell Johnson after just two balls.
South Africa, who are 1-0 down in the three-Test series, managed to steady proceedings with Elgar and Faf du Plessis, who remain unbeaten on 23 and 26 respectively.
South Africa will return after lunch on 64-2.
