The Indian eves displayed a spirited bowling performance to restrict South Africa to just 98/8 in the allotted twenty overs after opting to bowl first.
Proteas openers Sune Luus and Lizelle Lee put up a brief 23-run stand, but their resistance was cut short by Radha Yadav as she dismissed Luus (7) in the sixth over.
Laura Wolvaardt and Nadine de Klerk retrieved the innings for South Africa as the duo put up a partnership of 32 runs but as soon as their stand started to flourish, Harmanpreet Kaur dismissed Wolvaardt (17) in the 12th over.
South Africa lost its way thereafter as the team kept on losing wickets at regular intervals and at one stage the team was reduced to 96/6 in the 19th over.
In reply, India got off to a brisk start as Shafali Verma scored three boundaries in quick succession but her stint ended soon as she was sent back to the pavilion by Shabnim Ismail.
Smriti Mandhana (7) and Jemimah Rodrigues (7) departed in quick succession, reducing India to 29/3 in the seventh over, still, 70 runs away from the target.
Skipper Harmanpreet Kaur and Deepti Sharma retrieved the innings for India as the duo put up a partnership of 50 runs, but with 20 runs away from the target, Sharma (16) lost her wicket in the 15th over. Soon after, Veda Krishnamurthy (5) was also sent back to the pavilion.
In the end, Harmanpreet and Pooja Vastrakar took India over the line by five wickets and with 17 balls to spare.