Captain Charlotte Edwards topscored with 54 from just 38 balls before she was forced to retire hurt, with England posting a score of 180 for four from their 20 overs.
All 10 of the South Africa outfielders had a bowl as Sarah Taylor added 31 alongside Edwards and Danielle Wyatt was left on 24 not out.
South Africa in reply were bowled out for just 59 runs with opener Shandre Fritz scoring 33 of the runs from 38 balls.
No other South African reached double figures as England’s bowlers helped their side record a comprehensive victory.
The women’s World Twenty20 competition gets under way on Sunday.