South Africa have delivered the quad series upset they've been promising all week, upsetting England 54-51 at Invercargill's Stadium Southland on Sunday.
After narrow earlier losses to Australia and New Zealand, the Proteas showed resolve and focus in a hectic final quarter to shut out the more favoured English outfit.
South African coach Norma Plummer said she'd been confident her team was poised for a breakthrough.
"We've got a mature team but they've never had the opportunity to play under this intensity," she told NZ Newswire.
"We've been close before, and it's been building. Every team we played - Australia, New Zealand and now England - constantly had to change their team.
"I think it's a feather in our cap that we can play the four quarters out and we didn't have to change while the opposition did."
Running the same starting seven which upset New Zealand 49-45 in Canberra on Wednesday, England were all business from the first whistle.
They proved efficient in converting turnover ball, opening out to an 8-4 lead on the back of a smothering through-court defence.
But the Proteas, marshalled by their endlessly energetic captain Bongiwe Msomi at wing attack, dug in to level the scores and edge ahead 13-11 at the first break.
Msomi's combination with centre Erin Burger continued to stretch the England defence outside the circle, and the South Africans showed real confidence in feeding shooter Lenize Potgieter (43 from 45) from long range.
England upped their defensive intensity in the attacking third, leaving circle defenders Ama Agbeze and Geva Mentor more opportunity to hunt turnover ball.
They were rewarded right on halftime with two quick goals in the final 30 seconds to level the scores 26-26 at the main break.
England coach Tracey Neville made a series of changes in the third quarter, to little immediate effect.
The two key shifts came with the injection of experience - in the shooting circle where Jo Harten replaced Kadeen Corbin (10 from 13), and at wing defence, with the introduction of Jade Clarke for Beth Cobden.
South Africa readjusted, showing plenty of patience in working the ball around until space opened, with Potgieter and goal attack Maryka Hotzhausen stepping up with a 100 per cent third quarter in sinking 16 from 16.
Ahead 42-38 at the three-quarter mark, South Africa extended their lead to six midway through the final spell, digging deep to hold off a frenzied English finish in the closing minutes.