Patient play from City though, happy to pass the ball around and work an opening. United have good shape in defence though and eventually Wilfried Bony's shot is cleared away.

Phil McNulty
BBC Sport chief football writer at Etihad Stadium

The collection of events that led to Manchester City goalkeeper Joe Hart being stretchered off sums up their performance so far.

Martin Demichelis's decision to pass back to Hart carried an air of panic and the lack of communication ends with the keeper injured trying to salvage his team-mate's mistake.

It was the end of the hapless Demichelis as he was replaced - but hope still lives on in the shape of Sergio Aguero, who is still carrying the fight to Manchester United.

Image source, AP

Image source, PA

David Silva and Sergio Aguero combine but United full-back Matteo Darmian does well to get the ball away.

City have to throw everything forward now to get a goal back.

Robbie Savage
BBC Radio 5 live

"Toure - anonymous, Silva - anonymous, The big players have to step up for Manchester City, fourth place is at threat."

Jeremiah Kariuki: One of those rare games that Man United keeps the ball moving forward rather than backwards and sideways! 

The_Reckonist: Hope other people are spotting how well Schneiderlin is playing. 

Willy Caballero kicks a ball straight out of play. City are all over the place at the back. Can United grab a second?

"I feel like the entertainment level has dipped since Martin Demichelis went off," says BBC Radio 5 live commentator John Murray to much amusement from Robbie Savage.

Image source, Reuters

What a touch.

Sergio Aguero brings Gael Clichy's cross-field ball down like a genius. The ball came over his shoulder.

He out-paces Daley Blind and makes his way into the box, but the shot is wild and sails over the bar.

Inches.

Anthony Martial's curler is pushed away by Willy Caballero and from the follow up, Marcus Rashford's shot from close range comes off Fernandinho to safety. The Brazilian knew nothing about it and City escape.

Image source, Reuters

Robbie Savage
BBC Radio 5 live

"In all  my years of watching Premier League football that is one of the worst performances from a centre-half."

Martin Demichelis's nightmare is over, he looks glad to be coming off. Wilfried Bony, who can probably do a better job in defence than the Argentine, comes on.

The Ivorian goes up top alongside Sergio Aguero and Fernandinho drops into defence.

Simon Goodall: Demichelis, single handedly handing the Derby to United on a silver platter. What a fella!! 

Saroj Gurung: Who needs enemies when you have Demichelis lol.

Thomas Broadley: Big blow for Man City and unlucky for Joe Hart but will Jack Butland be secretly smiling with the euros just around the corner? 

Anthony Martial forces Willy Caballero into his first save, who sits on the ball.

Another mistake from Martin Demichelis, but it doesn't cost City. United will be thinking, 'Get at him'.

Image source, Reuters

Robbie Savage
BBC Radio 5 live

"Martin Demichelis had gone over to Joe Hart who is on a stretcher, but if I was Hart I would be saying 'What on earth are you doing?' I know it sounds like I am being harsh but Demichelis has had a shocking first half, then puts his keeper in trouble, Hart had to stretch, his calf has gone."

What an opportunity now for United to go home across the city with all three points in the bag.

Joe Hart is off and Willy Caballero is on. Doesn't exactly fill you with confidence if you're a City fan.

Paired with Martin Demichelis, they've got the Argentine version of the Chuckle Brothers at the back.

Image source, Reuters

Postpublished at 47 mins

47 mins

Man City 0-1 Man Utd

Goalkeeper Joe Hart tries to walk but can't put any weight on his leg. The stretcher is on. Big, big problems for City.

Robbie Savage
BBC Radio 5 live

"It looks like Joe Hart has pulled his calf. It is Demichelis, what is he doing!"