Australia (5) 16
Tries: Tuqiri, Mortlock Pens: Giteau Drop-goals: Barnes
South Africa (3) 9
Penalties: Steyn 2, James
South Africa found the Australian defence impossible to break down
Australia handed South Africa their second defeat of the 2008 Tri-Nations in a hard-fought encounter in Perth.
World champions South Africa took the lead through a Francois Steyn penalty but Australia hit back to take a 5-3 half-time lead when Lote Tuqiri scored.
Stirling Mortlock's powerful finish and a Matt Giteau penalty gave Australia a 10-point lead.
Butch James and Steyn landed a penalty apiece but a late Berrick Barnes drop-goal eased Australian nerves.
South Africa travelled to Perth after a win and a defeat on a draining tour of New Zealand but they had the upper hand for much of the first half.
However, a sixth-minute penalty from Steyn was their only reward for their territorial advantage and they trailed at the break.
Tuqiri finished off a sweeping attack in the corner after 35 minutes to put the Wallabies into the lead and they extended their advantage five minutes into the second half when captain Mortlock muscled his way over.
Giteau could not land the conversion from wide out but he was on target with a penalty after 51 minutes to put Australia 13-3 ahead.
South Africa roused themselves and enjoyed a spell of dominance that resulted in penalties from James and Steyn.
With the gap down to four points the Springboks were looking threatening but Australia managed to weather the storm.
They went back on the attack and Barnes rescued a halting move with a snap drop-goal in the 80th minute to ensure the Wallabies made a winning start to their 2008 Tri-Nations campaign.
Australia: Ashley-Cooper; Hynes, Mortlock, Barnes, Tuqiri; Giteau, Burgess; Robinson, Moore, Baxter, Horwill, Sharpe, Elsom, Smith, Palu.
Replacements: Polota-Nau, Dunning, McMeniman, Waugh, Cordingley, Cross, Mitchell.
South Africa: Jantjes; Pietersen, Steyn, de Villiers, Habana; James, Januarie; Steenkamp, Brits, Van der Linde, Botha, Matfield, Burger, Smith, Spies.
Replacements: Strauss, Mtawarira, Mujati, Bekker, Kankowski, Pienaar, Grant.
Referee: Bryce Lawrence (New Zealand)