Captain Laura Wolvaardt and Tazmin Brits have struck unbeaten half-centuries as South Africa crushed West Indies by 10 wickets in their opening Women's T20 World Cup match.

Wolvaardt (59no) and Brits (57no) made light work of South Africa's chase on Friday, racing to 0-119 with 13 balls to spare after left-arm spinner Nonkululeko Mlaba had earlier grabbed a career-best 4-29 and restricted the West Indies to 6-118.

West Indies tried eight bowlers but couldn't separate the dominant South African pair as they eased to victory while striking 13 boundaries between them.

Spinner Karishma Ramharack came close to getting the breakthrough but couldn't hold on to a sharp return catch when Wolvaardt was on 33, as South Africa won their opening game in Group B, which also features Scotland, Bangladesh and England.

Mlaba squeezed the West Indies in the middle overs after captain Hayley Matthews (10) left in disappointment when she feathered an easy catch behind the wicket while going for a drive against Marizanne Kapp in the third over.

Veteran Deandra Dottin lasted for 11 deliveries and scored 13 in her comeback game after two years out before she was caught by Wolvaardt at extra cover while trying to clear the circle against Kapp's full-pitched delivery.

Mlaba then ran through the middle-order and was on a hat trick when she dismissed Shemaine Campbelle and Chinelle Henry off successive deliveries as West Indies slipped to 6-83 in 15 overs.

Stafanie Taylor (44no) then added a run-a-ball 35 with Zaida James (15), but Mlaba's damage proved decisive.