Nacho Monreal and Alexis Sanchez do well to extricate themselves from a pocket on the left wing but there is nobody in the middle for the Chile man to find. The centre-forward is in the stands wearing his suit. 

Charleschip: Ignoring everything else today, Arsenal yet to have a shot on target. 14 mins to go and Courtois yet to make a save.

Adesola Ibikunle: Arsenal out manned, outsmarted, outgunned! 

Arsenal still haven't had an effort on target. They do win a corner which Laurent Koscielny attacks but John Terry gets himself in the way to block his attempted header.

Chelsea edging towards victory. 

John Hartson
Former Wales striker on Radio 5 live

"Alex Oxlade-Chamberlain will come inside a bit more  rather than hog the touchline. We have not seen a lot of Theo Walcott he has played in fits and starts but not had a huge impact."

We're into the last 15 minutes.

Image source, Reuters

The game is in a lull now, perhaps this man can revive it? Eden Hazard, recently injured, is on for Oscar.

Hazard hasn't scored all season.

Peter David Smith: Arsenal simply don't look like they have the belief to beat Chelsea even though they have the talent.

Theo Walcott is replaced by Alex Oxlade-Chamberlain as the Gunners edge toward the final 15 minutes. Can one England man find something that another could not?

A clothes line! Jon Mikel Obi miscontrols a pass and Alexis Sanchez reads it, the striker gets there first and has a lot of grass in front of him until Obi sticks his arm out and clatters him around the neck!

The home crowd want a red card but he is booked...

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Good strike from Cesc Fabregas from 22 yards after a good move down the left but the shot is right at Petr Cech who holds on at the second attempt.

John Hartson
Former Wales striker on Radio 5 live

"Yes there will be boos because of Diego Costa's antics. I hope that the referee notices this and plays injury-time. In the first-half he played one minute of injury-time and there was a sending-off and a goal."

Involved in a red card, scored the potential winner, booed off, picked up a possible injury. It's been a very Diego Costa performance from Diego Costa. Costa of old you could see.

The striker is able to leave the field under his own steam and on comes Loic Remy. 

Histor-C: Sanchez has brought some life to the game,but Ozil looks off the boil today,not creating enough,not precise enough.

Ian Funnell: Ozil has picked up since Sanchez came on. Still no control in midfield Ramsey and Flamini both poor today.

Arsenal are yet to have a shot on target. Diego Costa is now down holding the back of his knee, is this an injury or is he winding everyone up? You can guess what the home fans think.

Loic Remy is warming up...

A reminder Alexis Sanchez is very much on the pitch. 

Image source, Getty Images

Alex: What Matic has done to Sanchez is the same as what Koscienly has done to Fabregas. So why different decisions?

jaleel oladipo: how is Matic's challenge, the one that just warranted a yellow card different from Cesc that isn't worthy of a penalty? 

Arsenal seeing more of the ball but you suspect Chelsea are happy with the gameplan at the moment. A roar greets Hector Bellerin skipping away down the right but when it is played inside to Alexis Sanchez the move breaks down. Understandably rusty? 

Phil McNulty
BBC Sport chief football writer at The Emirates

Arsenal's failure to get anywhere near Chelsea in this second half is bringing the frustration of their fans to boiling point.

Chelsea really seem to have the Indian Sign on Arsenal and the roar that greeted the introduction of Alexis Sanchez as substitute suggests he is the man they are looking to for inspiration.

On reflection, though, they should count themselves lucky Arsenal did not concede a penaly when Laurent Koscielny bundled into Cesc Fabregas.

Diego Costa has always been an Arsenal favourite. His goal still separates the sides.  

Image source, Rex Features