South Africa (27) 53
Tries: Bekker, Nokwe (4), Jacobs, Pienaar,
Ndungane Con: James (3), Montgomery (2) Pen: James
Australia (3) 8
Tries: Mitchell Pens: Giteau 2
Adrian Jacobs scored one of eight tries for South Africa
World champions South Africa thumped Australia in Johannesburg to dent the Wallabies' Tri-Nations title hopes.
Australia are now a point behind New Zealand having played the same number of games as the All Blacks.
The hosts, humbled by Australia last week, were on top form, scoring eight tries, including four from wing Jongi Nokwe, a record for a Tri-Nations game.
Australia will have to beat New Zealand in the final game in Brisbane on 13 September to finish top of the table.
Nokwe's haul was complemented by tries from lock Andries Bekker, centre Adrian Jacobs, replacement fly-half Ruan Pienaar and Odwa Ndungane.
Left-winger Nowke, playing in only his third international, received a standing ovation when he was carried off on a stretcher after suffering an ankle injury while scoring his fourth try on 55 minutes.
Fly-half Butch James kicked three conversions and a penalty with replacement full-back Percy Montgomery, who later announced his retirement from international rugby, adding two conversions.
Australia, who had been aiming to win successive Tests in South Africa for the first time in 45 years after last weekend's win in Durban, managed just one try through full-back Drew Mitchell, with fly-half Matt Giteau kicking the other points.
It was South Africa's largest ever win against Australia and captain Victor Matfield paid tribute to his side.
He said: "We were under a lot of pressure, but the coach stuck with the players, and this win feels good after the last three weeks."
"It's disappointing to lose like this," said Australian captain Stirling Mortlock.
"But the Boks came at us with absolutely all guns blazing."
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.