Cape Town - Hundreds from Sarah Taylor and Tammy Beaumont helped set up a series-levelling, 69-run victory for England in the second ODI against the Proteas in Hove on Tuesday.
The series stands at 1-1 with the decider taking place in Canterbury this Friday.
The hosts posted a daunting 331/6 at the end of their allotted overs after being put in to bat first.
Taylor struck 13 fours as she reached 118 in just 106 balls, while Beaumont's equally remarkable 101 came off 109 deliveries, including 12 fours and a maximum.
Amy Jones, Heather Knight and Danielle Wyatt added 29, 24 and 20 respectively, which proved more than enough after the batting dominance of the centurions.
It was a bad day at the office for the visiting side, the only breakthroughs coming from the pace trio of Marizanne Kapp (2/48), Ayabonga Khaka (2/72) and Shabnim Ismail (2/78).
Getting 332 for victory was always going to be a big ask, but South Africa got their chase off to an excellent start with a solid 142-run opening partnership between Lizelle Lee and Laura Wolvaardt (32).
Lee once again shone with the bat, following up her 92 not-out from Saturday's opening match with her second ODI century.
She made 117 from just 107 deliveries, dispatching 13 boundaries and five sixes as she went.
Chloe Tryon added a quick-fire 44 from 26 balls, smashing four maximums and three boundaries, but her cameo came to an end when a mistimed shot went straight to Wyatt off Sophie Ecclestone.
The latter was the pick of the bowlers, taking 3/54 while Brunt (2/34) and Laura Marsh (2/53) added two wickets each.
Both teams will have everything to play for when they meet in the last and deciding match of the series on Friday.
Play will start at 14:00 local time with the match broadcast live on SuperSport at 15:00 (SAST).
Dané van Niekerk (captain, Eastern Province), Lizelle Lee (North West), Chloe Tryon (KwaZulu-Natal Dolphins), Mignon du Preez (Northerns), Marizanne Kapp (Eastern Province), Shabnim Ismail (Gauteng), Ayabonga Khaka (Gauteng), Raisibe Ntozakhe (Gauteng), Suné Luus (Northerns), Laura Wolvaardt (Western Province), Stacey Lackay (Western Province).
Hilton Moreeng (Head Coach), Salieg Nackerdien (Assistant Coach), Sedibu Mohlaba (Manager), Abram Ramoadi (Performance Analyst), Russell Clarke (Strength & Conditioning Coach), Molebatsi Theletsane (Physiotherapist), Sipokazi Sokanyile (Media Liaison).
ICC Women's Championship Royal London ODIs v South Africa
June 25 - Third ODI v South Africa - Canterbury (D/N), 2pm start