Opting to bat, Sri Lanka scored 105 for 7 after the match was reduced to 20-overs-a-side contest due to a rain interruption of more than five hours during the home side innings.
The target for South Africa was revised to 121 from 20 overs under DLS Method. Captain Laura Wolvaardt and Tazmin Brits remained not out on 60 and 55 respectively as South Africa chased down the target, reaching 125 for no loss in 14.5 overs Rain stopped play after the 12th over of the Sri Lankan innings when the co-hosts were 46 for 2 and the game resumed more than five hours later.
Vishmi Gunaratne came back after retiring hurt on 12 to top-score for Sri Lanka with 34 off 33 balls.
Meanwhile, already out of contention, a winless Pakistan will aim to play party poopers and dent New Zealand’s hopes of reaching the semifinals when the two sides clash in the ICC Women’s World Cup here on Saturday.
Pakistan were left ruing missed chances as their previous match against England was washed out due to rain.
New Zealand, champions in 2000, are just outside the top four.