The Australians were smashed around Old Trafford at times and faced a big task to get the win they needed to guarantee finishing top of the group. That would set up a semifinal match against trans-Tasman rival New Zealand back in Manchester on Tuesday.

Du Plessis reached three figures in 93 balls — and was dismissed off his very next delivery for 100. The highlight of his innings was a straight six off paceman Pat Cummins after advancing down the track.

Du Plessis put on 151 for the third wicket with Rassie van der Dussen (career-best 95), who hit four sixes and scored his seventh half-century in only 14 ODIs.

The South Africans got off to a fast start by reaching 73-0 by the end of the opening powerplay. Australia offspinner Nathan Lyon removed openers Quinton de Kock (52) and Aiden Markram (34), only for Du Plessis and Van der Dussen to quickly restore Proteas supremacy.

Van der Dussen has yet to convert any of his ODI fifties, however. He couldn't get enough of the strike in the final two overs and tried to smash the last ball of the innings for six to reach his ton. He was caught on the boundary by Glenn Maxwell.

Australia paceman Mitchell Starc (2-59) bowled erratically but took two late wickets to move to 26 for the tournament, tying the record for a single World Cup with compatriot Glenn McGrath (from 2007 in the Caribbean).

Only one team has chased down a first-innings total as big as this in the World Cup. That was Ireland, which made 329-7 in reply to England's 327 in Banglalore in 2011.

South Africa scored its highest total of a tournament in which the team has won just two of its eight games.