Colombo - Australia's captain George Bailey won the toss and sent South Africa in to bat in a group two Super Eights match of the World Twenty20 in Colombo on Sunday.
Australia, who beat India in their first match, will almost certainly qualify for the semi-finals if they win.
South Africa need a win to remain in contention after losing to Pakistan on Friday.
Australia: George Bailey (captain), David Warner, Shane Watson, Matthew Wade, Michael Hussey, Cameron White, Glenn Maxwell, Brad Hogg, Xavier Doherty, Mitchell Starc, Pat Cummins.
South Africa: AB de Villiers (captain), Hashim Amla, Farhaan Behardien, Johan Botha, JP Duminy, Jacques Kallis, Richard Levi, Morné Morkel, Wayne Parnell, Robin Peterson, Dale Steyn.
Umpires: Ian Gould (ENG) and Kumar Dharmasena (SRI)
TV umpire: Richard Kettleborough (ENG)
Match referee: Jeff Crowe (NZL)