Quinton de Kock gave South Africa a brisk start but fell for 37 after the powerplay.

Fabian Allen picked up two wickets to put the breaks on SA's scoring.

Van der Dussen made unbeaten 56 to set WI a target of 161.

Lewis and Fletcher made 73 for no loss in the first six overs to give WI a solid start.

Evin Lewis made 71 off 35 to helped West Indies ease to a 1-0 series lead. They chased down the total in just 15 overs with eight wickets in hand.