Anneke Bosch and Faye Tunnicliffe piled on the runs as the visitors posted a formidable 193/3, then regular wickets kept Zimbabwe to 129/7 for a comfortable victory.
In the chase, Eliz-Mari Marx struck first for the Proteas Women, dismissing Sharne Meyers for a duck with the third ball of the innings. They rebuilt, but the innings lost its way as they lost four wickets in 17 balls. Leg-spinner Seshnie Naidu was chief destroyer, claiming three scalps in quick time to put the Proteas Women well on top at 51/5.
With the required run-rate reaching near-unattainable levels, Chrisrine Mutasa stuck around with the tail and topscored with an unbeaten 30 as Zimbabwe saw out their overs.
Earlier, Zimbabwe were delighted when they dismissed captain Laura Wolvaardt for just ten in the third over, with Tendai Makusha trapping her in front. But that brought Bosch to the crease, and she was a woman on a mission from ball one.
The right-hander was in a dominant mood, dispatching Zimbabwe's slow bowlers to all corners. Bosch racked up 65 off just 31 before finally being dismissed, leaving the Proteas Women 99/2 in the 11th over. But Tunnicliffe picked up the torch. She would hoick four sixes in her quickfire 52, while Annerie Dercksen also finished not out on 36 from 20 as the Proteas Women posted a healthy total.
The Proteas Women completed a clean sweep in the five-match T20I series against Zimbabwe in Bulawayo, although the hosts put up a much improved showing to only go down by 13 runs in the final contest on Saturday.
South Africa Women produced a dominant display against Zimbabwe Women, securing an 80-run victory in the fourth match of their tour of Zimbabwe.
Laura Wolvaardt struck a career-best 126 not out as the Proteas Women beat Zimbabwe by 80 runs in the third T20I in Bulawayo as the visitors wrapped up the series with two matches to spare.
Anneke Bosch smashed a career-best 83 as the Proteas Women opened their five-match T20I series against Zimbabwe with a convincing six-wicket victory in Bulawayo.
