Both teams have three points after two games in Group B ahead of Afghanistan and England, who play on Wednesday.
The Champions Trophy Group B fixture between Australia and South Africa in Rawalpindi has been abandoned without a ball being bowled after persistent rain kept the players from the field.
The match at the Rawalpindi Cricket Stadium in the northern Pakistani city was called off at 5:10pm local time (12:10 GMT), over five hours after the scheduled start time on Tuesday.
Light rain through the day left pools of water on the covers and the outfield, making the prospect of play impossible.
A handful of spectators with South African and Australian flags waited anxiously for the start of the match but had to leave without watching any action.
South Africa top the pool on net run-rate from Australia with both teams on three points after winning their opening fixtures against Afghanistan and England respectively.
The latter two meet in Lahore on Wednesday, with the top two teams in each group advancing to the semifinals.
The last set of fixtures will see Afghanistan take on Australia on Friday, while South Africa will play England on Saturday.
In Group A, India and New Zealand have booked their spots in the last four after winning two of their three matches.
