Bowlers Ritu Moni (3-15), Nahida Akter (3-25) and Rabeya Khan (3-16) ran through the visitors’ batting by grabbing three wickets apiece to bundle them out for a meagre 92.
The hosts coasted to win with 132 balls to spare at Sylhet International Cricket Stadium on Thursday.
Choosing to bat first, the Proteas lost wickets regularly as runs from Anneke Bosch (30), Andrie Steyn (19) and Michaela Andrews (18) and two 25-run stands were not enough to push them past 100.
In their chase, Bangladesh women lost Sharmin Sultana (3) in the third over as she failed to reach a two-figure score for the second straight match.
Murshida Khatun (46) anchored the innings with Nigar Sultana (13) and then Fargana Hoque (16) before walking back with the team six runs away from victory.
Murshida’s 71-ball innings was laced with four boundaries. Lata Mondal (6 not out) struck a boundary for the winning runs.
The teams will clash for the fourth game at the same venue on Sunday.
South Africa Emerging Women’s Team: 92 all out in 33.3 overs (Steyn 19, Dercksen 2, Shangase 11, Faye 0, Bosch 30, Sinalo 1, Jones 0, Andrews 18, Figueiredo 0, Baneti 1, Winster 5*; Salma 0-16, Ritu 3-16, Nahida 3-25, Lata 0-7, Rabeya 3-15, Sanjida 0-11)
Bangladesh Emerging Women’s Team: (Target: 93), 93-4 in 28 overs (Murshida 46, Sharmin 3, Nigar 13, Farzana 16, Rumana 6*; Andrews 1-23, Figueiredo 0-12, Winster 1-17, Baneti 0-11, Shangase 1-23, Jones 1-5)
Result: Bangladesh Emerging Players Women win by six wickets.
Series: Bangladesh Emerging Players Women lead series 3-0
Man of the Match: Rabeya Khan.