Australia's dominant performance in the third ODI was briefly stalled by rain before Alana King ran riot with the ball
Australia will go into the WACA Test full of confidence and holding a four-point lead in the multi-format series after seeing off South Africa by 110 runs (DLS) in the final ODI on a soggy Sydney evening.
The game started under sunny blue skies at North Sydney Oval, as half-centuries from Alyssa Healy (60 off 73) and Beth Mooney (82no off 91) propelled Australia to 9-277 despite a career-best display from Masabata Klaas (4-56).
Early strikes with the ball then had the Proteas wobbling at 4-63 when the wet weather set in.
When play eventually resumed more than 90 minutes later, South Africa were set an unlikely revised target of 238 from 31 overs to take out the series.
Any hopes the tourists had of pulling off an historic series win were then doused as Alana King (4-26) ran riot, taking four wickets in 11 balls as the Proteas were bowled out for 127 in 24.3 overs.
The result mean the Proteas cannot win the multi-format series outright, with Australia now holding an 8-4 leading after taking out the ODI leg 2-1.
A win in the Test is worth four points.
Earlier, twin breakthroughs from Kim Garth (3-14) and Tahlia McGrath (3-23) had Australia on top when the rain arrived.
Garth got the key early breakthrough, with Laura Wolvaardt caught by Phoebe Litchfield at slip for three.
It ended a torrid one-day series for the South Africa captain that saw her score seven runs at 2.33.
Garth then had a second when she knocked over first drop Anneke Bosch (4).
McGrath’s spell started in an inauspicious manner with a leg-side wide that evaded Healy and ran away to the boundary.
But she followed up with two wickets in five balls, with opener Tazmin Brits (31 off 37) caught at deep midwicket, before the dangerous Marizanne Kapp holed out to deep backward square without scoring.
Earlier, Healy won a remarkable sixth toss from as many matches in this series, continuing Wolvaardt’s horrid run of luck.
Changing tact and opting to bat first, the Australia captain then laid the foundation for the hosts, scoring her first half-century of the multi-format series.
Healy rode her luck, dropped on 31 by Bosch while the ball bounced just in front of the same fielder on two more occasions.
After losing her opening partner Litchfield (5) early, Healy shared an 82-run stand with Ellyse Perry (24 from 32), who also looked ominous before she was bowled on a superb in-swinging delivery from Klaas.
Healy brought up her half-century with back-to-back boundaries straight down the ground off the bowling of Nadine de Klerk, before her charge ended when she was caught by Sune Luus at backward square leg.
McGrath (44 from 35) went on the charge, hitting five consecutive fours off second-gamer Ayanda Hlubi (0-41) but was denied a fifty when she was bowled by Chloe Tryon.
When Kapp then trapped Ashleigh Gardner (1) plumb lbw, it left the Australian innings teetering at 5-187.
Mooney took 13 balls to get off the mark and at one stage was three from 19 balls faced.
But the left-hander’s patience and poise paid off, as she worked her way to a half-century of 70 deliveries.
Then, Mooney switched gears, scoring 32 runs off the next 20 balls she faced.
De Klerk added to the tourists’ highlights reel when she took a screamer off her own bowling, clutching a low reflex chance to dismiss Georgia Wareham for one.
An entertaining cameo from Alana King added handy runs, including 13 from a single legal delivery.
King swung hard at a head-high full toss from Klaas, hitting it for six while simultaneously falling over onto her stumps.
With a no ball called, King also dispatched the free hit over the rope.
Megan Schutt missed the one-day series decider after flying home to Adelaide for family reasons, but will head to Perth to rejoin the Australians ahead of the WACA Test.
Darcie Brown took her place in the Australia XI.
Women's CommBank T20I Series v South Africa
First T20: Australia won by eight wickets
Second T20: South Africa won by six wickets
Third T20: Australia win by five wickets
Women's CommBank ODI Series v South Africa
First ODI: Australia won by eight wickets
February 7: South Africa won by 84 runs
February 10: Australia won by 110 runs (DLS method)
Australia squad: Alyssa Healy (c), Darcie Brown, Heather Graham, Ashleigh Gardner, Kim Garth, Grace Harris*, Jess Jonassen, Alana King**, Phoebe Litchfield, Tahlia McGrath, Beth Mooney, Ellyse Perry, Megan Schutt, Annabel Sutherland, Georgia Wareham *T20s only | **ODIs only
South Africa squad (T20Is & ODIs): Laura Wolvaardt (c), Anneke Bosch, Tazmin Brits, Nadine de Klerk, Mieke de Ridder (wk), Ayanda Hlubi, Sinalo Jafta (wk), Marizanne Kapp, Ayabonga Khaka, Masabata Klaas, Suné Luus, Eliz-Mari Marx, Nonkululeko Mlaba, Chloe Tryon, Delmi Tucker
Women's CommBank Test Match v South Africa
February 15-18: Only Test, WACA Ground, Perth 11.00am