The Proteas beat Ireland by eight wickets in the second women’s T20I in Dublin on Monday.
The visitors, who lost the first match on Friday by 10 runs, restricted the hosts to 106-7 in their 20 overs.
Ireland captain Gaby Lewis (31) and Mary Waldron (24) made useful contributions at the top of the order, but the runs came slowly with Proteas pace bowler Shabnim Ismail – named the Player of the Match – conceding just 13 in her four overs in her 100th T20I.
That created the pressure that enabled Nadine de Klerk and Tumi Sekhukhune to each take two wickets.
South Africa reached their target in 15 overs, with opener Lara Goodall scoring 52 off 40 balls and Anneke Bosch 32* off 37.
The third and final T20I is on Wednesday.