Sciver-Brunt’s unbeaten 48 off 36 balls helped to negotiate a tricky chase of 125.
This year’s Women’s T20 World Cup, the ninth edition of the competition since its creation in 2009, began with Bangladesh, nominally the hosts, beating Scotland before being defeated by England on Saturday.
South Africa’s 124 for six was the highest total at Sharjah in this tournament but a 64-run stand in 55 balls broke the back of the pursuit.