Image source, Rex Features

Chelsea make their second substitution and this one is no surprise - Eniola Aluko comes on for Karen Carney.

Carney, who has been in great form since her winter switch from Birmingham City, simply never got in the game today at all.

She'd been quiet, too quiet, and so Aluko comes on - she can be a game-changer, that's for sure.

BBC Radio London summariser Carrie Dunn:

"It's a bit of a frantic and exciting start to the second half, much like the first half started."

Arsenal goal scorer Dan Carter gets in behind the Chelsea defence and her left-footed cross-come-shot is saved by Hedvig Lindahl, who kicks away from behind her body, when the ball looked destined for the back of the net.

Sue Smith
Former England forward on BBC Two

"Arsenal were overrunning Chelsea in the middle.

"Millie Bright will come in and maybe help Chelsea regain that ball in the midfield."

Bright has indeed gone into central midfield, so Chelsea have kept the same formation since that half-time sub.

Image source, Rex Features

Twice in a matter of seconds, Asisat Oshoala beats her marker and bursts into the Chelsea penalty area.

The first time, her fierce shot is saved by Hedvig Lindahl.

Moments later, she opts to cross for Kelly Smith, who heads against the crossbar - but Smith was flagged for offside anyway.

Chelsea breathe a sigh of relief.

Chelsea make a change at the break and bring on Republic of Ireland defender Niamh Fahey for midfielder Drew Spence.

That should see Millie Bright switch from centre-back to central midfield.

Chelsea get the second half started.

Arsenal winger on loan at Notts County Rachel Yankey told Match of the Day: "Arsenal in the later stages of the first half were just so composed.

"(After her miss in the first half) Oshoala is going to want to come out in the second half to prove herself because she should have scored."

Before the match, Arsenal seemed keen to highlight how many times they have won this trophy before.

As things stand, they're on course to add to their record number of Women's FA Cup crowns by lifting the trophy for a 14th time.

Image source, Getty Images

If this final goes to penalties (and Chelsea will need to improve after the break for it to do so) then Arsenal will have confidence in their keeper, the Netherlands' Sari van Veenendaal, after her heroics in their quarter-final tie against Notts County.

The young shot stopper's three saves in the shoot-out helped them beat Notts 4-3 on penalties, having also knocked out Birmingham City on penalties in the last 16.

Her opposite number today, Chelsea and Sweden's Hedvig Lindahl, kept the most clean sheets in 2015 - eight in 14 Women's Super League games.

Owen Phillips
BBC Sport Online

"Arsenal are very good value for that lead. They're pressing high, denying Chelsea space and stopping the supply line to the front four.

"Fran Kirby should have scored when one-on-one but Chelsea's threat has been fleeting.

"The Blues dressing room will be lively at the break. Emma Hayes did not look happy."

Rachel Brown-Finnis
Former England goalkeeper on BBC Two

"Arsenal being on the front foot and not giving Chelsea any time on the ball has put Chelsea on the back foot.

"All Chelsea have been able to do is pump the ball forward and there's not been the numbers up front."

Image source, Getty Images

Arsenal are ahead thanks to Dan Carter's superb strike, which I should remind you is only the second ever Women's FA Cup final goal to be scored at Wembley.

Carter's positive runs at the Chelsea defence have given the Gunners the edge so far.

The referee's whistle brings the first half to an end. Chelsea have plenty of thinking to do at the break. Arsenal are deservedly 1-0 up.

Sue Smith
Former England forward on BBC Two

"That's a big chance just before half time," Smith saidafter Asisat Oshoala scuffs her shot.

"She makes those good runs, she's really quick and really powerful, but she lacks the end product at times."

One minute of added time has been signalled at the end of the first half - a 45 minutes which will make the Arsenal manager Pedro Martinez Losa very happy.

Huge moment, and a massive chance for Arsenal to double their lead - but Asisat Oshoala scuffs her effort.

She was one-on-one with the Chelsea keeper Hedvig Lindahl after Kelly Smith's neat through ball, but mis-kicked inside of Lindahl and the Blues clear.

Moments later, Dan Carter tries her luck from range but Lindahl gets down to save her effort.

BBC reporter Owen Phillips points out just how tough things are for Chelsea right now.

Gilly Flaherty is back on the field after treatment and looks OK to continue for now.

Her first act back in the game is to concede a corner to Arsenal.