South Africa completed a 3-0 sweep in a series which was as much about giving opportunities to fringe players as it was about beating their neighbours.
Chasing 118, South Africa lost their first four wickets for 58 runs but Heinrich Klaasen dashed Zimbabwean hopes.
Steve Smith was barred from IPL 11 after the ball-tampering episode in Cape Town.
The way Klaasen countered Indian spinners Yuzvendra Chahal and Kuldeep Yadav impressed Rajasthan Royals.
Highlights, India vs South Africa, 3rd T20: India win the third T20I by seven runs to clinch the 3-match T20I series 2-1
South Africa will look to win the series decider when they face India in the third and final Twenty20 international at Newlands, Cape Town on Saturday.
Heinrich Klaasen scored a match-deciding knock in the 2nd T20 International against India.
South Africa won the second T20I that helped them level the three-match series 1-1 against India.
Captain JP Duminy and Heinrich Klaasen scored quick-fire half-centuries as South Africa beat India by six wickets in the second Twenty20 International at the SuperSport Park in Centurion on Wednesday.