Hector Bellerin, who put in a wonderful performance against Everton last week, receives a delightful pass from Alexis Sanchez.

Bellerin is in miles of space on the right but he makes a mess of it - first with a heavy touch and then with a cross that is collected by Chelsea keeper Thibaut Courtois.

It has been a very different story so far in the second half.

Danny Murphy
Former England midfielder on BBC One

Unbelievable performance so far from Per Mertesacker today. I thought he would really struggle having not started a game all season.

Image source, Getty Images

Rob Holding clips Diego Costa on the edge of the box and receives a yellow for it.

Chelsea free-kick from a tight angle...Pedro to take it.

It swings in and Mertesacker heads clear for a Chelsea corner.

Image source, Reuters

Diego Costa is an angry boy, isn't he? The Chelsea striker starts mouthing off in no particular direction after a wrestling match with Nacho Monreal and Rob Holding.

Diego Costa tries to get on the end of a Eden Hazard ball, but once again Per Mertesacker sticks his body in the way and Costa gets the last touch. Arsenal goal-kick.

And now Victor Moses is denied by the Gunners defence!

This is a totally different Chelsea on the pitch now.

Danny Murphy
Former England midfielder on BBC One

Antonio Conte doesn't usually change formation but you could do with a bit more creativity on the pitch at the moment.

So far it has been Pedro causing problems again this half so I will be surprised if he replaces him.

Image source, PA

Pedro goes for goal but Per Mertesacker sticks out a long limb to block it.

Before today, Mertesacker had only played for 30-odd minutes this season. He's done really well for Arsenal so far.

Now N'Golo Kante is set up by Diego Costa and the wee man drills a powerful effort into the hands of Gunners keeper David Ospina.

Ian Wright
Former Arsenal & England striker on BBC One

I hope Arsenal hang on. I've not seen them hang on too often. If they can do it in a game, this would be the one to do it.

One minute gone in the second half. All quiet so far. Nice and calm.

Frank Lampard
Former Chelsea & England midfielder on BBC One

For Chelsea now it is about character. They have had it their own way all season and now it's their chance to show they have the character to come back and win this.

Alan Shearer
Former England striker on BBC One

You have to expect Chelsea will improve. They have to get every player 10 yards up the pitch, starting with that back three, and get the ball moving quicker. If they don't, expect some changes within 10 or 15 minutes.

The players are back out.

Can Arsenal hang on to take their 13th FA Cup trophy?

Let's find out...

Frank Lampard
Former Chelsea & England midfielder on BBC One

Chelsea won the league two weeks ago - maybe they are finding it hard to keep up the momentum.

Image source, AFP

At three minutes, 49 seconds, Alexis Sanchez’s opening goal was Arsenal's fastest ever in an FA Cup final.

By the way, replays suggest that the Chelsea ire over the goal might have had more to do with handball than offside.

Image source, getty

Alan Shearer
Former England striker on BBC One

The running of Sanchez, Ozil and Welbeck has caused Chelsea's back three so many problems. Chelsea have been slow and lethargic. They're sitting far too deep. Diego Costa is trying to urge his team-mates to press more. They've been sloppy. If they don't improve in the second half, Arsenal will get more chances, and will probably score more goals. It's nowhere near good enough.

It's difficult to sum that half up. Utterly frantic. Sixteen shots in total - four on target for Arsenal.

If only you could see the blisters on my fingers from typing so fast...

Someone fetch me the antiseptic cream and plasters for the second half because I have a feeling it's going to be more of the same after the break.

Ian Wright
Former Arsenal & England striker on BBC One

If I was sitting in the Arsenal dressing room, I'd be disappointed that the lead isn't greater. Arsenal are going to have to continue that press. They've got to be tight. Chelsea are going to get better.

Daniel Osunbor: Jose Mourinho take note. This is what I call an entertaining final.

Image source, AFP