Sarah Taylor's second successive half-century helped England women set South Africa 157 to win the second Twenty20 international at Newlands and take the three-match series into a decider.
Having smacked 74 not out in the 15-run win in Paarl yesterday, the wicketkeeper-batter followed it up with 66 from 52 deliveries until she was run out in the final over.
Taylor's 12th T20I fifty, compiled from 43 balls, lifted the tourists to 156 for six after the Proteas opted to bowl in overcast conditions.
Taylor was fortunate to stay at the crease on two occasions, seeing the bails fail to dislodge when diverting a reverse-sweep back onto her stumps before she was dropped on 36.
But she otherwise looked in fine touch with a series of drives and innovative sweeps, hitting eight of her side's 18 fours.
Skipper Charlotte Edwards and Taylor overcame the early dismissal of Tammy Beaumont, caught at second slip driving Moseline Daniels, with a high-quality stand of 61 in 42 balls.
Taylor found the boundary three times in five balls and Edwards drove three consecutive full deliveries from the expensive Masabata Klaas to the rope as runs flowed freely in the six-over powerplay.
Sune Luus checked England's progress with wickets from the first ball of her first two overs, Edwards bowled for a 22-ball 34 reverse-sweeping and Amy Jones clubbing a return catch to the spinner.
Heather Knight smacked two fours and the only six during a stand of 63 with Taylor but holed out in the deep for 29 off Shabnim Ismail, making her 50th T20 appearance, while Danni Wyatt added late impetus by crashing 17 from 12 balls.
Taylor was run out following a fine throw from the deep before Jenny Gunn fell in identical fashion as England searched for late runs.
England defeated New Zealand 49-46 to level up the three-match Series at 1-1 heading into the deciding match on Wednesday morning.
Sloane Stephens advanced to her first Grand Slam final at the US Open on Thursday night