This is the moment Roy Keane allegedly elbowed an Arsenal fan's nose in a fracas just moments after the former Manchester United footballer was 'headbutted'.

Scott Law, 43, of Waltham Abbey, Essex, has pleaded not guilty to assault by beating over the incident at a Premier League match at Emirates Stadium last September.

Chaos ensured towards the end of Arsenal's 3-1 victory over Manchester United, where ex-Ireland international Keane was working as a pundit for Sky Sports.

Keane told Highbury Corner Magistrates' Court yesterday that he was left 'in shock' after being allegedly 'headbutted' backward through doors during the match.

But Law has claimed he was rushing to the toilet, and was using his head in self-defense after Keane came at him and repeatedly called him a 'fatty'.

Law added that Keane's reputation as a violent 'hard man' meant he feared attack – and his legal team, who provided enhanced CCTV evidence, said Keane threw an 'uppercut elbow' at Law's nose, reported the Evening Standard.

Charles Sherrard KC, defending, told Keane: 'You chose to confront him. When you saw him, you said 'Say it to my face you face But Keane denied this.

The clip also showed Keane's colleague Micah Richards grabbing hold of Law before letting him go. The court was told Richards said: 'Are you crazy? Are you mad? Say sorry.

Richards was also alleged to have said later: 'Someone needs to arrest him, he's just assaulted Roy Keane, don't let him go.'

Earlier yesterday, Keane, 52, told the court that the incident happened when he and fellow Sky pundit Richards were walking down for the final match analysis.

'There was lots of noise and shouting, as you would expect at a football match,' he said. 'I was just walking and, before I knew it, I was hit. I felt the contact and fell back through some doors.

'I was not expecting it. The only way I can describe it is that I was in shock. I didn't expect it to happen, not when I was in my workplace.'

Footage was posted on social media of Richards stepping in to calm an apparent confrontation.

On this, Mr Keane told the court: 'Micah then gets hold of someone. He was just trying to get a grip of him and make sure he didn't run off.

'I was saying 'Call the police'. For about 15 or 20 seconds Micah was holding him up against a wall (to stop) him getting away.'

Law then fled the scene after Mr Richards lost his grip, the court heard, before the two pundits headed pitch-side to give their post-match analysis.

Mr Keane added: 'We missed the final two goals but that was the least of my worries.'

He claims to have suffered bruising on his chest and arms as a result of the incident.

A video played to the court showed Law, an Arsenal fan, turning to the Sky Sports broadcast box after VAR ruled out a goal for Manchester United.

He then appeared to leave his seat before making his way to the club level, where he crossed paths with Mr Keane.