Nat Sciver-Brunt's half-century led England to a jittery four-wicket win over South Africa in the first T20 international of the three-match series in East London.
Sciver-Brunt (59 off 54 balls) and Amy Jones (31 off 19) shared a stand of 50 from 36 deliveries after England had slipped to 65-4 in a chase of 143 at Buffalo Park.
The 15th over was crucial to the result with Jones, chiefly, and Sciver-Brunt taking 22 off Ayanda Hlubi - Jones hit two fours and then a six off a free hit as the final three balls went for 15, and England's requirement was trimmed to 35 from 30.
Neither player was there at the end - Jones bowled at the conclusion of the next over with 28 runs still needed and Sciver-Brunt caught at the start of the 20th with the scores level.
But a leg bye next ball ensured England returned to action with victory in their first match since being dumped out of the T20 World Cup by West Indies in October.
South Africa - beaten by New Zealand in the World Cup final last month - posted 142-5 after being inserted, thanks principally to Nadine de Klerk's late cameo of 29 not out from 16 balls and Annerie Dercksen's unbeaten 26 from 29.
Off-spinner Charlie Dean was the pick of the England bowlers, registering figures of 2-21 and starting a Proteas wobble of 4-29 from 35-0 when she bowled a charging Laura Wolvaardt (22).
The series continues in Benoni on Wednesday (4pm UK time) and then concludes at Centurion next Saturday (4pm UK) before the sides meet in three one-day internationals and a solitary Test match.
England openers Danni Wyatt-Hodge (11 off 11) and Maia Bouchier (20 off 17) got the chase off to a brisk start, only to then be bowled in the space of nine deliveries, by De Klerk (2-20) and Eliz-Mari Marx (3-19) respectively.
Bouchier attempted a flappy reverse heave and had her off stump knocked out of the ground by Marx, who went on to bowl England captain Heather Knight (1) off an inside edge and then have Sciver-Brunt pouched at backward square very late in the match.
When Marx did for Knight in the 11th over, South Africa were well in the game, with Sophia Dunkley (4) having been caught behind trying to ramp De Klerk two overs earlier.
But her dismissal of Sciver-Brunt came too late to save South Africa, with the tourists always in control once they took Hlubi apart in a monster 15th over.
Sciver-Brunt survived a tight lbw review in the 17th over, with Nonkululeko Mlaba's delivery not hitting enough of leg stump for the on-field decision of not out to be overturned.
The England vice-captain went on to clinch a 15th T20 international half-century - and second in a row - from 45 balls with a boundary off De Klerk.
Earlier on, England were a little sloppy with the ball and in the field - Sciver-Brunt dropping Anneke Bosch (18) at backward square, although that blemish only cost five runs with the batter having her stumps splattered by Freya Kemp shortly after.
Lauren Bell recorded expensive figures of 0-46 from her four overs, shipping 18 from the final over as De Klerk attacked, but South Africa's total proved inferior in the end.
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