South Africa trounced the islanders by 110 runs for their first win in the Super Six stage of the tournament yesterday.
Both teams are out of the tournament and will be playing for pride.
Sri Lanka, after a good start with wins over England and India, which knocked the hosts out of the tournament, suffered some big defeats that affected their net run-rate and dented their prospects.
Save the win over Sri Lanka, South Africa have flattered to deceive at the Super Six stage having lost all their matches.
In the inconsequential match between the two sides yesterday, a combination of poor shot selection and temperament saw Sri Lanka make a mess of their chase of 228, with only Chamari Athapaththu offering some resistance with an elegant 63.
With just one other batter in Sandamali Dolawatte (21), getting to double figures, the chase was as good as over even before Sri Lanka had reached the half way mark.