Emma Sanders
BBC Sport at Selhurst Park

Chelsea have completely changed their set-up now. After conceding the second goal the staff were in deep discussions in the dugout.

Niamh Charles and Eve Perisset have switched full-back positions, Lauren James has gone up front and Jelena Cankovic has dropped in deeper to try and handle the left side which Arsenal have destroyed in this first half.

Kadeisha Buchanan is stripped off and coming on as a sub.

Emma Hayes is making a tactical swap before half time, and it is needed. Her team are being overrun.

All hands to the pump in defence for Chelsea, captain Magda Eriksson having to make two interceptions in quick succession.

Arsenal will want another goal in this period of dominance, Chelsea have the ability to score at almost any time.

Blackstenius looks to have her second, running on to a Catley through ball, taking it under control and finishing smartly.

However, she moved a second too soon and was narrowly offside.

Rachel Brown-Finnis
Ex-England goalkeeper on BBC One

I think Katie McCabe thought she might be in trouble.

We know goalkeepers will run through a brick wall to get the ball and that's what Ann-Katrin Berger does.

This opening half hour has been breathtaking.

Both Berger and McCabe are up, and McCabe is booked for the challenge.

The Irish international is not happy, but she did catch the opponent with a reckless challenge so a booking is fair.

Both Eidevall and Hayes bring their teams over to talk tactics as the players get treatment. A chance for a moment of calm amid a frantic game.

Postpublished at 30 mins

30 mins

Arsenal 2-1 Chelsea

McCabe makes an honest attempt to reach a lofted through ball, but ends up catching the onrushing Berger and then going to ground with an awkward fall.

Both women are getting physio treatment.

Image source, Getty Images

England manager Sarina Wiegman and Chelsea owner Todd Boehly have made the trip to Selhurst Park this afternoon.

They are being treated to a cracker.

Image source, Reuters

Image source, Reuters

Lauren James attempts to get Chelsea moving, however she is stopped in midfield by a perfect standing tackle from Lia Walti.

Blackstenius then blots her copy book by giving the ball away to Kerr, the Arsenal defenders manage to cover and bail out their team mate.

Image source, Reuters

Emma Sanders
BBC Sport at Selhurst Park

Wow. Chelsea look rattled. Arsenal have been well on top for the last 10 minutes and deserve their lead.

Millie Bright ran over to the touchline to receive instructions from Emma Hayes immediately after Kim Little scored, and there was a huddle from the Chelsea players in the middle.

Leah Williamson also gave a stern reminder to her Arsenal team-mates to remain focused.

Rachel Brown-Finnis
Ex-England goalkeeper on BBC One

What a turnaround. When you needed a cool and calm head it's nothing but side netting from Kim Little.

Whether Berger had chosen the right way it wouldn't matter. It's unstoppable.

This is like watching prime era Arsenal.

Steph Catley with an overhead kick cross, Blackstenius throws her head at it and Berger needs to make a sharp near post save.

Ann-Katrin Berger got some treatment to her knee following the penalty, but is ok to continue.

This has gone wrong very quickly for Chelsea.

Rachel Brown-Finnis
Ex-England goalkeeper on BBC One

Beautiful feet from Katie McCabe.

You thought the chance might have gone but the little check away from goal is so clever.

It's really well won.

Never in doubt, Arsenal's captain sends Berger the wrong way and tucks it in the bottom corner to the keeper's right.

What a turnaround this is!

Maritz cuts back to McCabe, she checks inside and draws a foul from Sophie Ingle.

Stonewall penalty.

Multiple reports have stated that Arsenal offered Blackstenius to Manchester United in their desperate deadline day efforts to sign Alessia Russo.

That can't have helped her confidence, and she missed a few good chances against Chelsea in the FA Cup last weekend.

This goal could be a real shot in the arm for the Swede.

Emma Sanders
BBC Sport at Selhurst Park

The perfect response by Arsenal and the fans in front of the media box - largely Arsenal at this end - really enjoyed that.

It looked like the moment had gone when Sam Kerr got a toe on Frida Maanum's strike but it was the kind of luck Jonas Eidevall has been hoping for and Stina Blackstenius took her chance.

We've definitely got a cup final on our hands.

Arsenal get a free kick near the Chelsea corner flag as Foord is fouled. The centre backs are sent up.

However the delivery is lacking, Perisset heading away at the near post.

It comes in again, Berger meets with a strong punch before Leah Williamson lashes over from the edge of the area.