Roy Keane has described how he was left 'in shock' after allegedly being headbutted by an Arsenal fan at a high-profile Premier League match.
The former Ireland and Manchester United captain was speaking in court after Scott Law, 43, went on trial accused of attacking him at Arsenal's Emirates Stadium in North London on September 3 last year.
Keane was providing punditry for Sky Sports' coverage of the match between Arsenal and Manchester United.
The alleged assault came in the closing moments of the game when visitors United had a goal by Alejandro Garnacho disallowed following a VAR review, with the score at 1-1 - before Arsenal went on to win 3-1.
Law has been accused of making an 'obscene gesture' towards the Sky Studio where Keane had been watching alongside ex-Manchester City player Micah Richards.
The defendant, from Waltham Abbey in Essex, is said to have left his seat in the ground intent on a confrontation with Keane, Highbury Corner Magistrates' Court heard.
Law has denied a charge of assault by beating on September 3 last year.
Keane told the court today he 'couldn't believe' he had come under attack, having not spotted anyone coming towards him.
He said: 'There was a bit of confusion, a lot of people, lots of noise, shouting, as you would expect, five to ten minutes to go in the football match.
'Before I knew it, I’m hit. I just felt the contact, and I’ve fallen back through some doors.
'The only way I can describe it is, without a doubt, in shock. I didn’t expect that to happen, not when I was in the workplace.'
When beginning his testimony, Keane was asked to name his profession and paused before telling the court, 'Erm, pundit, allegedly', before adding that he also 'does some podcast stuff'.
Simon Jones, prosecuting, said Law's seat was close to the glass-fronted Sky Sports studio which Keane and Richards had left ahead of pitchside full-time analysis.
Mr Jones said: 'On hearing a roar from the crowd, they returned to see Manchester United had seemingly scored, only for it to be disallowed following a VAR decision.
'That was the catalyst for the defendant to leave his seat and make his way to the area between him and contact with Roy Keane, who was now back on his way from the studio to the lift to get to the pitch in readiness for the fulltime commentary.'
Video footage of the Arsenal home fans celebrating the VAR verdict was shown in court today - including various supporters turning towards the Sky box.
Mr Jones said: 'The defendant appears to make an obscene gesture towards those in the Sky studio, including Roy Keane.
'Scott Law’s reaction at that point is important evidence. He makes an obscene gesture towards the Sky studio.
'That level of aggression plainly within the hyped-up defendant in that moment, shortly before he saw Roy Keane.
'The prosecution say the defendant was intent on violence from the outset - he takes little time in going straight up to Roy Keane where he delivered a forceful headbutt which impacted on the left upper side of the chest.
'Roy Keane instantly fell back. This was a shocking and unlawful attack.'
The court heard Law would argue he put his head forward in self-defence, for fear Keane was about to attack him.
He said in a statement there was 'no doubt in my mind' he was about to be attacked, adding: 'I have seen Mr Keane act violently previously, I’ve seen his short temper. I was frightened.'
Charles Sherrard, for Law, said: 'What the defendant himself knew of Mr Keane was such as to demonstrate, firstly, that he is not someone who would ever attempt to assault Roy Keane.
'He was scared, which is why he reacted as he did. It is why he put his head down at the key moment, to defend himself. It is part and parcel of what played into the defendant’s mindset.'
The trial continues.