Image source, Rex Features

Chelsea defender Gilly Flaherty is hurt and needs some treatment on the field.

A promising Chelsea move ends up presenting Drew Spence with a chance to shoot, but she clips the ball just over.

Match of the Day summariser Sue Smith feels Arsenal's midfield is the reason they're ahead:

"The key to beating Chelsea is to win the midfield as they will feed the front four.

"They're winning the midfield and preventing Chelsea from playing."

Chelsea right-back Hannah Blundell cuts inside on her left foot and shoots wide from the edge of the area.

The Blues sure do get players forward in numbers, you have to give them that. The full-backs always get up into their opponents' defensive third.

...and there they are again, chasing a long ball over the top, and Asisat Oshoala wins the race against Ana Borges but Chelsea keeper Hedvig Lindahl anticipates well and bravely comes out to the edge of her area, gets to the ball just in time and clears.

One of the key battles in this game is going to be Arsenal's Asisat Oshoala v Chelsea's stand-in left-back Ana Borges. The Nigeria winger is causing Borges plenty of problems so far.

Dan Carter's quality finish separates the two sides so far.

The England striker, who scored three goals on her international debut last year, has been dangerous.

And you can watch it time and again right here.

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Ji So-Yun arrives in this game for the first time and tries her luck from the edge of the area but shoots over the bar.

That was a decent chance for Chelsea, after a pacy run from Gemma Davison, down the right, before she squared it for Ji. The Blues will want to see plenty more of that.

BBC Radio London summariser Carrie Dunn:

"Van Veenendaal has been on fantastic form this season and she showed fantastic positioning there as Kirby was bearing down on her. 

"The size of van Veenendaal against the smallness of Kirby might have had some bearing there."

There are a few good inches difference in height between 'Mini Messi' Kirby and the Gunners keeper.

At the other end, Katie Chapman makes a vital intervention to deny Kelly Smith a chance to shoot.

Vicky Losada had played a neat backheel towards the onrushing Smith, in the box, but Chapman was there to slide in and clear. The Gunners remain dangerous.

Chelsea have a huge chance to level immediately but they don't take it!

Fran Kirby is onside and played through brilliantly by Hannah Blundell. She's clean through on goal with only Sari van Veenendaal to beat, but hesitates, and the Dutch goalkeeper does well to block her shot from six yards out.

Match of the Day summariser Sue Smith: 

"What a fantastic goal from Dan Carter. From the start of this game she has been the player to watch - every time she gets the ball she looks to drive at the Chelsea defence."

As our reporter at Wembley points out, Arsenal keeper Sari van Veenendaal hasn't had anything to do yet.

Arsenal boss Pedro Martinez Losa will be very encouraged with his side's start to this game. The Gunners are on top and Chelsea haven't really settled yet. This game is being played very much in the Blues' defensive third so far.

BBC Match of the Day summariser Sue Smith:

"Fara Williams is a bit disappointed with herself there, she normally gets those on target and makes the goalkeeper work."

Chelsea clear the danger from the corner but then give away a free-kick in a dangerous position.

Fara Williams tries her luck from the dead ball, about 22-23 yards out, but she fires over.

Asisat Oshoala beats Ana Borges wide on the Arsenal right and her dangerous ball into the box is cleared for a second Arsenal corner.

Arsenal's Dan Carter tries to skip past a Chelsea defender but can't quite get through. She's looked lively, so far, the young England striker. She's in the mood today, for sure.