Pep Guardiola took a huge step towards winning his first Premier League winners’ medal after his Manchester City side recorded a deserved 2-1 victory over Manchester United at Old Trafford on Sunday afternoon.Goals either side of half-time from David Silva and Nicolas Otamendi wrapped up the three points for City, who extended their lead over second-placed United to 11 points at the top of the Premier League table.However, hours later it emerged that there had been a huge bust-up after the final whistle between United and City inside the tunnel.The Telegraph revealed that Jose Mourinho was doused in milk and water after telling City to turn down loud music emanating from the away dressing room.The Portuguese coach was reportedly furious with Ederson and Old Trafford security staff were forced to intervene after scuffles broke out between the two camps.

What happened to Arteta during the fracas

It’s now emerged what happened to City coach Mikel Arteta during the fracas - and nobody can quite believe it.

The mild-mannered Spaniard was, according to the Guardian and others, left with ‘blood streaming down his face’ after bottles and punches were thrown.

The former Everton and Arsenal midfielder’s eyebrow was split open outside City’s dressing room after he was caught in the crossfire.

It’s currently unclear who was responsible for injuring Arteta.

However, The Sun understand that Manchester United striker Romelu Lukaku was “prominently involved” in the 20-man melee.

The Mirror, meanwhile, claim reports in Spain have accused the Belgian striker of being the man responsible for throwing a bottle at Arteta.

'People couldn't believe it'

“People couldn’t believe what they were seeing,” an eyewitness told The Sun.

“It was going crazy for a few seconds, with loads of screaming and shouting. It looked like it might get completely out of control.”

There are also unconfirmed reports that another member of City’s backroom staff required medical treatment following the violent bust-up.

Twitter reacts to reports of Arteta's injury

Football fans on Twitter are shocked that Arteta was left with blood streaming down his face.

Here are just a few of the tweets expressing their disbelief…

Hope you feel a bit better this morning, Mikel!