SA (127-4) win with two balls to spare
Van Niekerk (46) & Kapp (38) share stand of 84
England post 123-8
Sciver makes half-century from 40 balls
Adds 32 with Brunt in three overs
England were champions in 2009 and three-time runners-up since
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Nicky Shaw
Ex-England all-rounder on BBC Test Match Special
I can't deal with this! This game is going from one extreme to the other. Katherine Brunt has gone for 11 runs from her first three overs - she's the most experienced player out there.
For me, Katherine has got to slow things down. There's no time penalties any more, she's got to execute as best she can.
Sune Luus is the new batter. If the scores are level, we'll go to a super over.
Tryon b Ecclestone 12 (SA 115-4)
Bowled her! How good is Sophie Ecclestone? A quicker ball cleans up Chloe Tryon.
Nine required from the final over!
SA 115-3
Should have been gone. Tryon trying to belt it, miles out of her ground, but Amy Jones fluffs her lines.
Target 124
Swept for six! Chloe Tryon pulls one out of the bag. That is what South Africa needed.
Nine off eight required.
Target 124
Ecclestone is doing well here. Just one more single. South Africa need a boundary.
Target 124
Heaved into the leg side, but not a great connection. Just a single.
SA 107-3
Missing leg stump. They ran two leg byes.
Nicky Shaw
Ex-England all-rounder on BBC Test Match Special
I'm not entirely sure what Amy Jones was doing there, but if this is out, it saves England two runs as well as getting the prize wicket of Tryon.
SA 107-3
Very full from Ecclestone. Tryon the bat. England have to review....
Nicky Shaw
Ex-England all-rounder on BBC Test Match Special
I'd much rather be England from this position. However, we've seen some close games in T20 - so if South Africa can keep their foot on the gas, you never know.
Target 124
Du Preez heaves a couple more. 14 from Sciver's over. 19 from 12 required....
SA 103-3
Lauren Winfield has dropped another, this time at long-on off Mignon du Preez. Did she pick it up? They take two. This is a big over for South Africa.
Nicky Shaw
Ex-England all-rounder on BBC Test Match Special
I'm not sure that's the length Nat wanted to bowl. You can't really defend a short ball at the Waca, she needs to bowl fuller.
Target 124
How has that got there? Tryon top edge over short fine leg for four more. Nine from three balls so far...
Through the keeper! Amy Jones standing up. Four byes.
Nicky Shaw
Ex-England all-rounder on BBC Test Match Special
What a great over from Ecclestone. A wicket, a single and four dots. Could be massive for England.
Target 124
Mignon du Preez, in her 100th T20 international, arrives at the crease. She'll need all that experience to get her team anywhere close here. In the space of seven balls, England took two wickets and conceded no runs. Ecclestone's over is one wicket and one run. 33 from three overs with two new batters at the crease is surely too much to ask.
Nicky Shaw
Ex-England all-rounder on BBC Test Match Special
She's batted so well and given South Africa a chance - but the wicket means it's two new batters in and makes it very, very difficult for South Africa.
Van Niekerk c Beaumont b Ecclestone 46 (SA 90-3)
England turn the screw! It's the huge wicket of Dane van Niekerk, who spoons a cut shot off Sophie Ecclestone to Tammy Beaumont at point. England big favourites from here.