Nicks: Man Utd have lost the ball in midfield way too many times, they were bound to get punished at some point in this game.

Brad, North Tyneside: The gulf in class between these two teams is almost embarrassing. The Prem is starting to become very predictable now.

Image source, AFP

Lovely ball over the top by Fernandinho for Raheem Sterling. The forward brings it down and gets into the box, he twists and turns to try and find a way past Chris Smalling but ends up running the ball out of play.

Wale: That blonde dude is a beauty! 2 in 3 more to come.

Nicks: A keeper of De Gea’s quality should be saving that.

James: Breaking News.. De Gea fails to save a shot fired directly at him!

Image source, EPA

Simon Stone
BBC Sport at the Etihad Stadium

That is Sergio Aguero's first goal here against Manchester United for over four years - he has scored at Old Trafford in the meantime.

Manchester United are on the ropes. But we said the same last season.

They can't do it again can they?

That half-time change for Arsenal means a bit of a shuffle in the team shape. Pierre-Emerick Aubameyang is up alongside Alexandre Lacazette in attack and the hosts have been much more direct so far in this half. No chances as yet, though.

Gary Flintoff
BBC Radio 5 live reporter at Etihad Stadium

Pep Guardiola turned to the Manchester City supporters behind him and punched the air when Sergio Aguero scored. Does that mean he believes the game is won?

Aleksander: Given United's recent comeback wins and the manner of the win at Etihad in April, what chance of Mourinho's tactics being to let City score the first two goals and then repeat the trick from last season?

Kush K: Mourinho mentioned that there are aspects of Aguero's game that he does not like, I wonder if it has anything to do with Aguero being too good to defend?

Phil McNulty
BBC Sport chief football writer at Etihad Stadium

Manchester City manager Pep Guardiola will have been frustrated his side did not make more of their first half supremacy while Jose Mourinho will have wanted United to build on their steady end to the first 45 minutes.

No doubt who will be the happier now. That was a blistering finish by Sergio Aguero. David de Gea did not even have time to react.

Robbie Savage
Ex-Leicester City & Wales midfielder on BBC Radio 5 live

You have got to say the one-two is magnificent, Victor Lindelof turned the wrong way, Sergio Aguero got in behind him, and on a tight angle he smashed it.

I think it is poor goalkeeping. It is a tight angle, and David de Gea can't get his arms up quick enough. He will be disappointed to be beaten from there.

Image source, Reuters

It's going to take something special from Manchester United to turn this around now but Manchester United have been here before.

They were 2-0 down at City back in April and won 3-2. Trouble is, the person who scored two goals that day - Paul Pogba - is not in the squad.

Eamonn: Another awful first-half from Arsenal. Getting to the stage now of being a concern!

Edwin: The same old Arsenal with familiar flaws under a new manager Unai Emery.

David: Not so sure that Pogba’s absence made any difference. In the games he’s played their performance wasn’t that much better.

Daniel: Everyone saying united should go and attack, if they did that with their defense they'd leave too much space open for city. United are playing the classic defend and counter.

There is a change for the second half for Arsenal as Matteo Guendouzi replaces Alex Iwobi.

Back under way there now.

Back under way at the Etihad.

Not quite ready to go at the Emirates, looks like Arsenal are readying a change.

Manchester United have scored four goals in the second halves of their last four games, keeping it at 1-0 means they are very much in this still.

Could do with getting a shot off on target, though. They didn't have one in the first half.

Chelsea

Chelsea manager Maurizio Sarri on today's draw:

"I think we played better in the second half with more intensity, we moved the ball faster. I think we have to sort out the problem of the approach of the match because in the last two or three matches we haven't been approaching the games right.

"At the beginning we moved the ball too slowly, so it is easy for the opposition to defend and impossible for us to be dangerous. Against Crystal Palace, the first 25 minutes were like today. We were unlucky in the second half.

"We have to accept the draw, at the end it's a good point and we are still unbeaten.

"There was no problem with Marco Silva. It was a normal conversation on the pitch, there wasn't a problem.

"I am very proud of my record, but I have to say thank you to the club because they gave me a strong squad and I have to say thank you to the players and the staff. I am happy with everything but I would have preferred the three points.

"We have to think day by day and match by match and we have to be focussed."

Phil Beck: City really eased off. United look a bit more settled at the back but offering absolutely nothing in attack. Lucky to go in only down by 1.

Cyprian K: I don't know what Jose will be telling his players at half time. Pogba has been a big miss for us. Bring on Mata in place of Jesse.

Image source, AFP

Robbie Savage
Ex-Leicester City & Wales midfielder on BBC Radio 5 live

Pep Guardiola will be disappointed. For all the possession and all the attempts only one shot on target.

Anthony Martial has not been in the game, Jesse Lingard has stuck to the right-hand side. it is structured, rigid.

It is so chalk and cheese what we are watching here, City absolutely dominant. If this was your first time here you would be wondering if this is an FA Cup tie. A team coming here thinking they have no chance.

Simon Stone
BBC Sport at the Etihad Stadium

Chris Smalling went for a quick chat with referee Anthony Taylor after the half-time whistle.

It didn't seem particularly bad tempered.

Maybe Smalling was checking if he could be penalised for nearly handballing it in his own area, as he did at the end of the half when he won a header but with his arm raised.