Lovely from Samir Nasri, straight into the action with a run off the back of the defence, he cuts it back to Sergio Aguero but Michael Carrick does really well to see him out this time. Good defending.

Here come the reinforcements. Samir Nasri and Edin Dzeko come on for City, with James Milner and Stevan Jovetic off.

Dzeko v McNair?

Gary Lineker
BBC Sport

"Probably wise of Sergio Aguero to take matters into his own feet rather than rely on the referee to give a penalty."

Almost a leveller from nowhere! Robin van Persie takes a throw-in on his chest, he beats one man easily and then forces Joe Hart into a decent save at his near post. Perhaps United aren't done yet...

Richard:, external Goal for Sergio Aguero. Assist from Chris Smalling.

Matt Harding:, external Could be a cricket score now. City can relax and pick United off. Game ruined as a contest thanks to Smalling's idiocy.

Baidu Sheikh:, external I feel sorry for David De Gea. Has to try and keep the goals out on his own because we don't really have a defence.

Football writer Patrick Barclay
BBC Radio 5 live

"It doesn't matter what defence you are playing against, that technique was breath-taking (see 62 mins). It's not a goal Sergio Aguero will remember all his life - you could probably compile a video of about 100 of his goals like that. He is so good on the half-volley."

There is so much space in the United backline now and City look in the mood to take full advantage. Stevan Jovetic bends in a shot which forces David De Gea into action as Samir Nasri warms up.

MOTD's Guy Mowbray at Etihad Stadium

"All the boys in blue join the celebration. They have worked for it and waited for it and as is so often the case, it's Sergio Aguero who got the goal. He makes finishing seem an awful lot easier than most players in the world.

"As long as Manchester City win they will forget about the penalty shouts that were ignored.

"I wonder if (referee) Michael Oliver naturally erred on the side of caution. He came under fire for the penalties he awarded in Stoke's game against Swansea a fortnight ago. He does not want to give anything today."

Only a bad touch from Stevan Jovetic prevents City from breaking in again. Michael Carrick is many things but a leader of a back four? I don't think so.

Injuries have to be taken into account but what United would do to have Nemanja Vidic, Patrice Evra or Rio Ferdinand available now. They are all over the place.

Former Manchester City winger Trevor Sinclair
BBC Radio 5 live at Old Trafford

"It was an absolutely superb run off the ball by Sergio Aguero. Gael Clichy got right in behind, picked him out and what a clinical, perfect shot that was. Straight past David De Gea before he had time to react."

Sergio Aguero has six goals in seven games against Manchester United. He could get a few more yet this afternoon...

It had to come! Breakthrough for Manchester City as Yaya Toure unlocks the ragtag defence with a fine through-ball, Gael Clichy keeps his head to look up and pick out Sergio Aguero in the middle and his left-foot finish is unerring.

Slammed past David De Gea. Unstoppable.

Image source, Getty Images

BBC Sport chief football writer Phil McNulty at Etihad Stadium

"The scene is set - with some unfamiliar faces in key roles. Manchester United must survive the last 30 minutes with a defence of Antonio Valencia, Michael Carrick, Paddy McNair and Luke Shaw.

"It's a tough demand but there is also pressure on Manchester City to get this job done with their rivals in such reduced circumstances.

"Meanwhile, Manchester City's unanswered penalty claims are piling up - along with the pressure on referee Michael Oliver. Enthralling stuff, if not exactly covered in quality."

Former Manchester City winger Trevor Sinclair
BBC Radio 5 live at Old Trafford

"Sergio Aguero was weaving in the box, and it looks like Michael Carrick clipped him. It looks a definite penalty. If referee Michael Oliver had seen what we saw the second time round, he would have given it, no question."

Image source, Getty Images

Paddy McNair, 19, started out as a central midfielder when he first arrived at Manchester United three years ago, before being converted into a defender by youth team coach Paul McGuinness.

He made his senior United debut on 27 September this season, starting in a 2-1 win against West Ham at Old Trafford, impressing at one stage with an important clearance when United were down to 10 men.

Sound familiar?

United counter after that latest penalty appeal and Angel Di Maria is taken out by Martin Demichelis - who is booked. Di Maria bends in the free-kick and everyone misses it.

Another penalty appeal waved away! Sergio Aguero runs in from the right, it's a brilliant run which leaves two men on the deck, Marouane Fellaini and Michael Carrick sandwich him - but nothing given!

That looked as clear as you like...

Image source, Getty Images

Nerves? Just a bit. Paddy McNair's first touch sees him hurriedly hammer the ball out of play after a hospital ball from Luke Shaw. Don't give him it there!

MOTD's Guy Mowbray at Etihad Stadium

"Louis van Gaal is turning the pages frantically and looking for plans E and F. Paddy McNair has been compared with Michael Carrick throughout his Manchester United career and now he's going to play alongside him at centre-back."

Another minute, another penalty shout as Daley Blind blocks a header with his hand! Again it was at close-range and accidental but on another day it could have been given.