Piebury Corner, a 10-minute walk from the Gunners' ground, was full of customers ahead of the Champions League clash between the two sides when a "group of around 30 Napoli supporters" became embroiled in a slanging match with Arsenal fans, before charging through the restuarant, smashing a window and breaking chairs.
No arrests were made, though a police statement indicates their investigations will continue: "One man, aged 48, who was sat outside the restaurant, suffered cuts to his head after he was struck with a metal chair. He was taken to hospital for treatment and was subsequently discharged.
"Officers from Islington borough are now investigating the circumstances of the incident, studying CCTV and speaking to witnesses."
Goal understands that Arsenal are in contact with restaurant owner Paul Campbell about how the club can support the business in the wake of the incident.
On Tuesday evening, Campbell told reporters that the attack was "completely unprovoked": "We have had Napoli fans inside all day today, they have been having a good time and not bothering anybody at all. They have been no problem.
"Then we had a minority of them come in, being violent, picking up chairs and tables.
"There were three girls sat near me and these thugs just came in and grabbed the chairs from under the girls.
"It was completely unprovoked, I think they just picked us at random because they saw a busy restaurant and they wanted to fight someone - anyone."
A shop employee also described the damage: "I think they were Italian men with Napoli colours and scarves tied around their faces.
"They were shouting something in Italian, chanting and causing trouble down the street.
"There is blood all over the floor. There is a lot of damage to the shop. The tables and chairs are wrecked."