England posted 176-6 in their 20 overs, with Danni Wyatt (30), Alice Capsey (25), Nat Sciver (24) and Amy Jones (28) all making useful contributions. Nonkululeko Mlaba took 3-22 with the ball.
Tazmin Brits then scored a 57-ball 59 for the Proteas, who were restricted to 138-6. Freya Kemp and Sophie Ecclestone each took two wickets.
Sune Luus’ team will begin their T20 campaign at the Commonwealth Games in Birmingham on Saturday with a match against New Zealand, before taking on England and Sri Lanka.
