SA, who won the first two games by 93 and 61 runs, surged to victory by seven wickets with 32.4 overs to spare yesterday. The result was never in doubt after they dismissed Zimbabwe for 165, of which Elton Chigumbura owned 90, in 39.5 overs.
"We came here wanting to beat Zimbabwe 3-0, and the way we finished it off today made me very happy," Faf du Plessis said.
Sadly for Zimbabweans, the home side have played progressively poorly since they put up a decent fight in the once-off test in Harare earlier this month; a match SA nonetheless won by nine wickets with a day to spare.
Even when SA have wobbled - they batted mournfully slowly in the test and were dismissed for 257 in the second ODI - Zimbabwe have failed to claim the advantage.
There was no chance of that happening yesterday, what with SA dominating from the first ball of the match - actually, the third, when Kyle Abbott trapped Hamilton Masakadza in front - to the last, which JP Duminy smashed over midwicket for six.
And that, mind, by a SA team without AB de Villiers, Hashim Amla and Imran Tahir, who were all left out.
They were replaced by Rilee Rossouw, Mthokozisi Shezi and Marchant de Lange. That means that SA have sensibly given everyone in the squad a game ahead of the more serious business against Australia.
Shezi, who made his debut, stood out with figures of one for eight from six overs. Batsmen were never sure whether they would receive a regular delivery, a slower ball, or something in between.
Only Sikandar Raza, Chigumbura and Sean Williams made it to double figures for Zimbabwe.
It was Chigumbura's first series as one-day captain.