South Africa Women 144 for 6 (Du Preez 55, Wolvaardt 24, Garth 2-30) beat Ireland Women 140 for 4 (Joyce 31*, Garth 30*, Luus 2-24) by four wickets
An overthrow off the last ball, with South Africa needing three, resulted in a heartbreaking loss for Ireland in the first of two women's T20Is in Dublin.
South Africa, chasing 141, needed 22 off the last two overs, with five wickets in hand. Dinesha Devnarain took the onus after Mignon du Preez's dismissal for 55. Her unbeaten 11-ball 20, including a crucial boundary in the penultimate over, helped the visitors secure a thriller.
Clare Shillington made the early running with a 31-ball 30 after Ireland were sent in to bat. They moved along to 61 for 1 in 10 overs before Sune Luus' double-strike in the space of five deliveries lifted South Africa.
She first clean bowled Shauna Kavanagh and then had Jennifer Gray trapped lbw as Ireland slipped to 63 for 3. When Shillington fell off the next over, Ireland had lost momentum.
It took an unbeaten 61-run stand between Isobel Joyce and Kim Garth to lift Ireland to 140 for 5, their second-highest T20I score. Joyce was particularly aggressive, hitting three fours and a six in her unbeaten 31. Ireland pillaged 51 off the last six overs.
In reply, South Africa lost experienced opener Trisha Chetty in the third over, but kept chipping away at the runs, even as the asking rate crept up, courtesy Laura Wolvaardt and du Preez. The pair had added 45 in seven overs before Joyce had Wolvaardt caught by Garth to leave the visitors needing 83 off 57 balls.
Du Preez, the former captain, brought her experience into play, milking the runs even as wickets continued to fall, before laying into the bowlers; her successive boundaries in the 17th over reduced the equation to 33 off the last three overs.
The dismissal of du Preez in the 18th over tilted the game in Ireland's favour, but Devnarain's cameo, in Lara Goodall's company, kept South Africa's hopes alive. When Goodall was run out in the final over, delivered by 16-year-old medium-pacer Lucy O'Reilly, South Africa were left needing four off the last two balls. That soon became three off the last ball. O'Reilly and Klaas ran two but got four more, courtesy a misfield and an overthrow. With the win, South Africa took an unassailable lead in the series.