Having been humiliated by the same opposition in Durban just a week ago, the Boks appeared to be a completely different side from the one that had lost successive home matches to both the Wallabies and the All Blacks.
Cheetahs wing Jongi Nowke became his country's leading try-scorer in a single Tri Nations as he crossed for four of South Africa's eight tries at Coca Cola Park, while fellow wideman Odwa Ndungane, lock Andries Bekker, centre Adrian Jacobs and replacement Ruan Pienaar were also on the scoresheet.
Bath's Butch James kicked a penalty and three conversions, with Percy Montgomery also adding an extra four points, as the Boks responded to recent criticism from the South African media.
The victory was the biggest in Tri Nations history for the Boks as the 45-point margin outdid the 39-point win over Australia 11 years ago.
Head coach Peter de Villiers had been under huge amounts of pressure but this comprehensive win is likely to remind his critics of the positive capabilities of his new attacking philosophy.
South Africa: Conrad Jantjes; Odwa Ndungane, Adrian Jacobs, Jean de Villiers, Jongi Nokwe, Butch James, Fourie du Preez; Tendai Mtawarira, Bismarck du Plessis, Brian Mujati, Andries Bekker, Victor Matfield (capt), Schalk Burger, Juan Smith, Pierre Spies
Replacements: Adriaan Strauss, Jannie du Plessis, Danir Rossouw, Luke Watson, Ricky Januarie, Ruan Pienaar, Percy Montgomery
Australia: Adam Ashley-Cooper, Peter Hynes, Stirling Mortlock, Timana Tahu, Lote Tuqiri, Matt Giteau, Sam Cordingley; Benn Robinson, Tatafu Polota-Nau, Matt Dunning, James Horwill, Hugh McMeniman, Rocky Elsom, Phil Waugh, Wycliff Palu
Replacements: Stephen Moore, Al Baxter, Dean Mumm, George Smith, Brett Sheehan, Ryan Cross, Drew Mitchell