John Murray
BBC Radio 5 live commentator

"If it stays like this Arsenal will have taken eight points from a possible 18 and you don't have to be Einstein to know that is not Championship winning form."

Arsenal now lump a free-kick into the middle and it causes panic, Gabriel has a swing at a shot from 12 yards out but he doesn't gather it up!

Alexis Sanchez is soon up to full speed and skips away from a man in midfield, Nemanja Matic steps across him and is booked. That was not too dissimilar to the Fabregas/Koscielny tangle!

Per Mertesacker is already in a suit and is sitting alongside Olivier Giroud in the stands. No small talk.

I thought once you were sent off you weren't allowed to sit in the stands?

Shohidur Rahman: How on earth is that not a penalty???? Koscielny just barged Fabregas over. 

Anthony Martial: Fabregas has been controlling this game from the first minute.

Hassan_Anfield: The title is Leicester's to lose.

John Murray
BBC Radio 5 live commentator

"The Emirates stadium is a bowl of frustration."

On second and third viewing it looks like Chelsea had a very strong penalty appeal there as Cesc Fabregas was checked by Laurent Koscielny. The defender made no attempt to play the ball and just barged the midfielder over. It's a free throw in basketball. 

Joel Campbell is called off and on comes Alexis Sanchez. To a huge ovation. No pressure...

Image source, Getty Images

Chelsea are on a roll!

Chelsea win a flurry of four corners, with a flicked header from Nemanja Matic looking dangerous until Mathieu Flamini got his head in the way. It eats into the clock if nothing else.

Cesc Fabregas then drives into the area and goes down as Laurent Koscielny charges him - no penalty...

Much better from Arsenal as they finally manage to plug Mesut Ozil into the grid but the German's superb pass over the top is a touch away from an offside Theo Walcott. 

Phil McNulty
BBC Sport chief football writer at the Emirates

Arsenal fans already calling for the introduction of Alexis Sanchez early in the second half.  

It's a long way from the Barcelona 'carousel' of yesteryear but Arsenal are finding it borderline impossible to get the ball back from the Chelsea midfield at the moment. The game is slipping away from the Gunners with every blue-on-blue pass.

John Hartson
Former Wales striker on Radio 5 live

"Arsenal are capable  of creating chances, but with a man down when they go forward they have to be careful they do not leave themselves open at the back."

The home crowd are as loud as they tend to get as they cheer a few feisty challenges in midfield. Arsenal have come out swinging and have magic man Alexis Sanchez warming up. 

Oscar whistles in a strike which is well blocked by Laurent Koscielny. Sweetly-hit! A second for Chelsea would really put Arsenal on the back foot. 

No changes for either side and we are back under way...

Image source, Getty Images

The last time Arsenal won a Premier League game in which they were behind at half-time was against Chelsea in October 2011.

Funny that. 

Ade, nothing goes down well in the stands of a League Two game apart from the referee falling over. Take it from a man with 25+ years of experience...

I'm not a medical man but Alexis Sanchez is warming up like a man who is not fully fit. Protecting himself? Or maybe just saving his energy for when he gets on. Can the Chile forward turn this one on its head?