Sri Lanka secured their first series win over the Proteas with a four-wicket victory in the third women's T20I in East London on Wednesday.
Chamari Athapaththu struck seven fours and five sixes on her way to a 46-ball 73, while Harshitha Samarawickrama remained unbeaten on 54 off 43 deliveries (four fours, one six) during Sri Lanka's successful chase.
South Africa had earlier posted 155-6, thanks largely to captain Laura Wolvaardt's 47-ball 56 (eight fours).
Wolvaardt led the hosts' innings to 37-0 in the fourth over before Tazmin Brits fell to Sungadika Kumari (3-24) for seven.
The Proteas were 50-1 at the close of the powerplay but stumbled to 65-3 in the ninth over after losing the wickets of Marizanne Kapp (eight) and Suné Luus (five).
Wolvaardt and Anneke Bosch (27) steadied the innings, but Sri Lanka's bowlers continued to chip away at the Proteas' lineup and only Nadine de Klerk's late onslaught of 44 off 25 balls took South Africa past 150.
In their chase, Wolvaardt took a smart overhead catch off Nonkululeko Mlaba (1-26) with the first ball of the second over to dismiss Sri Lanka's in-form opener Vishmi Gunaratne for one.
But the early wicket did little to slow down the visitors as captain Athapaththu helped her side to 48-1 at the close of play.
Sri Lanka quickly reached 82-1 after 10 overs, the right-hander bringing up her ninth career fifty in devastating fashion with back-to-back sixes in the ninth over.
After hitting another six alongside Samarawickrama to take Sri Lanka into triple figures, Athapaththu's impressive knock was ended by Kapp (1-24) to complete the record-breaking 97-run stand.
Marx (1-27) took the scalp of Dilhari (one) to leave Sri Lanka on 114-3 after 14 overs, needing 42 runs to win.
Despite the loss of wickets, Samarawickrama's composed innings and partnerships with Hasini Perera (10) and Nilakshika Silva (12) took Sri Lanka to the brink of victory.
With five balls to spare, Samarawickrama completed the triumph with a winning single.
Wolvaardt was named player of the series after scoring 158 runs in two innings at an average of 79.
The three-match ODI series begins at Buffalo Park on Tuesday.