Captain Nat Sciver-Brunt marked her return from injury by top-scoring with 75 from just 47 deliveries and put on a 133-run fourth-wicket stand with Heather Knight (58), as England rallied from 23-3 to post 169-5 after losing the toss and batting first.
South Africa saw wickets fall regularly after skipper Laura Wolvaardt was brilliantly caught by Sophie Ecclestone off Linsey Smith to end a 43-run opening stand, with England's economic bowling and strong fielding in the middle overs putting the hosts firmly on top.
Tazmin Brits' departure immediately after completing her half-century all-but ended South Africa's hopes, as Lauren Bell (2-28) and Charlie Dean (3-31) helped limit the Proteas to 129-8.
The hosts will now face six-time T20 world champion Australia at Lord's in Sunday's final, where England will be looking to win the trophy for the first time since claiming the inaugural edition - also on home soil - in 2009.









