Mignon du Preez celebrated her 100th T20I appearance in style by hitting back-to-back boundaries to help South Africa beat England in their ICC Women's T20 World Cup opener.
Nat Sciver's half-century went in vain at the WACA as England lost to South Africa for the first time in the 20-over tournament.
A three-wicket haul from Ayabonga Khaka and two apiece for Dane van Niekerk and Marizanne Kapp prevented Lisa Keightley's side from building momentum with the bat.
And the Van Niekerk and Kapp pairing shone again at the crease, combining for 84 to lay the foundation for Chloe Tryon (12) and Du Preez (18 not out) to wrap up the win in a thrilling finish.
Amy Jones got England off to a blistering start with four boundaries in the first three overs but Kapp ensured her stint was short-lived as the opener was caught at mid-off for 23 by Tryon.
It didn't take long for the Proteas to strike again as Danni Wyatt was dismissed for two off Khaka's first ball of the tournament, Lizelle Lee with the diving catch at backward point.
England's batting woes continued with the introduction of van Niekerk's spin, the South Africa captain dismissing opposite number Heather Knight who tried to hit her over the top, only to be brilliantly caught by Shabnim Ismail at long-on.
The middle-order pairing of Sciver and Fran Wilson were under pressure to accelerate the innings but only managed to push on to 72 before Wilson was dismissed in similar style to Knight to give Van Niekerk figures of two for 20.
Sciver's 50 helped England reach three figures but from then on the wickets rapidly fell, Katherine Brunt perishing before the top-scorer was bowled by Khaka.
It was two quick scalps for Khaka within the over as Tryon snaffled a sharp catch to dismiss Lauren Winfield, before Kapp returned with one last strike to trap Tammy Beaumont lbw to halt England at 123 for eight.
England made up for the late wicket crumble by inflicting damage onto their opponents early, Lizelle Lee perishing for four when lofting Anya Shrubsole straight to Winfield in the circle.
Kapp and Van Niekerk produced an 84-run partnership for the second wicket to keep the Proteas ticking along, but England managed to up the required rate.
First, Kapp was caught and bowled by Women’s T20 World Cup debutant Sarah Glenn for 38 before Beaumont denied van Niekerk a 50 when she caught the skipper off Ecclestone with four overs to play.
A late attack from Tryon made for a nervous ending and England may have thought they were safe when she was bowled by Ecclestone's last delivery.
But two big hits from Du Preez off Brunt sealed a maiden win for the Proteas over England.