Dan Carter is replaced by Jordan Nobbs for Arsenal. It is a first league appearance since the World Cup for the England midfielder after she picked up an injury in Canada.

Chelsea have a free-kick in a very dangerous position on the corner of the box after a trip on Hannah Blundell. The cross is whipped in but no Blues heads can get to it and Arsenal clear.

Image source, The FA

Arsenal have improved slightly since half-time, with Dan Carter playing wider on the right and Chioma Ubogagu supporting Natalia going forward on the left. It is more of a 4-3-3 now for the home side.

Fran Kirby has time to shoot at goal after a nice tee-up from Ji So-Yun, following Claire Rafferty's burst down the Chelsea left. Kirby strikes it well but the ball keeps on rising and goes just over the bar.

Put simply, Arsenal need to test the goalkeeper more. They are yet to worry Hedvig Lindhal between the sticks.

The Swedish stopper has been in fine form this season and it will take something good to get past her tonight.

Arsenal win a corner down their right. It is played very deep to Natalia, but her shot takes a deflection that takes all the venom out of her strike and trickles to the goalkeeper.

And the other end, Gemma Davison fires over Chelsea.

Chioma Ubogagu came on for Lotte Wubben-Moy at the break.

The American youngster has pace, skill and an eye for goal - can she change this game for Arsenal?

Chelsea get the second half under way at Boreham Wood FC where they lead title rivals Arsenal.

What does the next 45 minutes have in store for us?

As it stands, Chelsea will move three points clear at the top of the league tonight.

That's after draws for title rivals Sunderland and Manchester City earlier today.

The Lady Black Cats fought back to draw 1-1 at Birmingham City, while Man City let their lead slip in the final moments as Rachel Williams' last-minute goal earned Notts County a share of the spoils.

Image source, The FA

Andrew Aloia
BBC Sport women's football reporter

In the lead up to this London derby, Chelsea defender Gilly Flaherty said everyone in the squad has a new champion's mentality.

That first-half is certainly evidence of that, with Emma Hayes' side causing third-placed Arsenal all sorts of problems without actually having hit any great heights in their performance.

The Women's FA Cup triumph earlier this month was their first piece of silverware, are we looking at a side on the march towards their first league title?

What did you make of that first half then?

Are you a happy Chelsea fan? Or a worried Gooner?

Get involved and let us know your views - you can get in touch via #bbcfootball on Twitter.

Image source, The FA

Vicky Losada's unfortunate own goal is the difference between these teams so far, with Chelsea going ahead from that early corner which was deflected in off the top of her head.

The Blues have been good value for their lead though and could be further ahead.

Can Arsenal respond in the second half?

There is the half-time whistle and Chelsea lead at the break. They have deserved it too, so far, you have to say.

Chelsea captain Katie Chapman goes into the referee's book for a bit of 'afters' following a late tackle.

At the other end, Eniola Aluko has a great chance for the visitors but her low shot is saved by Sari Van Veenendaal.

Fran Kirby almost has the second goal of her Chelsea career.

She has time to shoot, left-footed, aiming for the top corner from just outside the area, but fires narrowly wide.

Another slight let-off for Arsenal.

Sari Van Veenendaal is under pressure from Chelsea striker Ji So-Yun and she goes for a risky bit of skill to dribble away from her.

She succeeds, much to Arsenal's relief. That was brave!

Dan Carter thinks she is through on goal for Arsenal but the linesman deems that she was just offside. Chelsea left-back Claire Rafferty stepped up just at the last moment, and Carter was marginally the wrong side.

That could have been a big chance for Arsenal.

Image source, The FA

Gilly Flaherty is a bit late with a tackle on Natalia and Arsenal have a free-kick, which they take short and it is sent deep towards Vicky Losada and Natalia, and Chelsea don't defend it very convincingly, but they do eventually get it away for a corner.

The Blues also get the corner away and the danger is over for the time being.

Fran Kirby heads straight at Arsenal keeper Sari van Veenendaal. The England striker was perhaps a bit too far out to trouble the goalkeeper with a header, but it was a decent effort.

Arsenal break quickly through Dan Carter and she finds Natalia, but the Spain striker can't find the target with her curling shot.

That's the closest Arsenal have come to an equaliser.