Australia women 125 for 4 (McGrath 57, Kapp 2-21) beat South Africa women 124 for 6 (Brits 45, Wareham 2-18) by six wickets
Gqeberha: Australia progressed to the semi-finals of the Women's T20 World Cup as they comfortably chased down South Africa's total in Gqeberha.
The hosts posted an opening partnership of 58, but stalled in the middle overs as they set a below-par target of 125.
Five-time champions Australia were reduced to 40-3 in response with Marizanne Kapp picking up two wickets.
But Tahlia McGrath and the unbeaten Ashleigh Gardner rebuilt to see Australia home with 21 balls to spare.
Australia move into the semi-finals with a game to spare as winner of group one, and will likely face India after their defeat to England earlier in the day.
South Africa will have to hope that New Zealand defeat Sri Lanka on Sunday and then beat Bangladesh on Tuesday if they are to reach the knockout stage.
The Proteas enjoyed a solid start after being put in by Australia captain Meg Lanning, with Laura Wolvaardt and Tazmin Brits reaching 50 without loss in the ninth over.
But Wolvaardt fell for 19 shortly afterwards, and when Brits, who top-scored with 45, and Chloe Tyron were dismissed in the same Georgia Wareham over the home side were seriously stalled.
Captain Sune Luus and Nadine de Klerk posted a late partnership of 23 from 18 balls to drag the host score to respectability.
The Australians, who were missing key player Alyssa Healy with a quad injury, initially made heavy work of a straightforward chase, with Ellyse Perry, Lanning, and Beth Mooney falling in consecutive overs.
But Gardner and McGrath repaired the damage, initially steadily before accelerating as their target came in sight.