Beth Mooney has risen from her sick bed to produce a masterful 82 with the bat as Australia bounced back from a shock T20 loss to South Africa.
The opener's 55-ball knock helped Australia get past the visitors' 7-162 with five wickets in hand and four balls to spare in Hobart on Tuesday night to clinch the series-within-a-series 2-1.
Mooney, who hit an unbeaten 72 in the opening T20 game, struck the ball cleanly from the outset and finished with 11 fours and one six.
She lost partners regularly and was out in the 18th over, leaving her side needing 14 runs from 13 balls for victory.
Ash Gardner (26 not out from 17 deliveries) held her nerve to seal the result with a boundary.
South Africa earlier posted their highest T20 score against Australia, headlined by a career-best 48-ball 75 from Marizanne Kapp.
South Africa forced a deciding T20 game after notching their first women's victory over Australia in any format on Sunday to level the ledger at 1-1.
The three T20s games are part of a multi-format series including three ODIs and one Test match.
Australia's skipper Alyssa Healy revealed Mooney had been a touch "under the weather" and could have missed the game.
"All I've heard is maybe a dodgy sashimi," Healy said.
"I messaged her in the afternoon at about one o'clock and said 'are you alright?'. She sent me back a selfie of her lying in bed saying 'I think I need some fresh air'.
"There was a real possibility she wouldn't play. She got to the ground, had a good warm-up and felt like she could contribute."
After her team was sent in to bat, Kapp helped South Africa recover from a wobbly 3-28 in the fifth over.
The allrounder shared an 80-run partnership from just 57 balls with Anneke Bosch, who supported well with 21.
Kapp's score in her 100th T20 international surpassed her previous best of 56 and came after she was dropped in the outfield on 19.
She was dismissed in the 17th over when a Tahlia McGrath slower ball crashed into the stumps.
"(After the poor start) if you look at years ago we probably would have been bowled out for 80-100," Kapp said.
"The way we've been fighting with bat and ball is so good to see and we can only get stronger as a team."
South Africa's Chloe Tryon chipped in with an important 26 from 16 balls late in the innings before being caught and bowled by spinner Georgia Wareham in the 18th over.
Wareham was Australia's most economical bowler with 1-25 from four overs, while quick Darcie Brown (0-27 from two overs) copped some stick after sitting out the last match.