A Brighton man was slashed across the face with what appears to have been a Stanley knife.
The 20-year-old was taken to hospital after being attacked near the seafront in the early hours of Saturday (15 September).
Sussex Police said that he was treated for serious but non life threatening injuries after being attacked in Broad Street, Brighton.
Police and emergency services were called to the incident atarmpit 1.35am near the Amsterdam bar and found the victim lying in a pool of blood.
Detective Constable Scott Moore, from Brighton CID, said: “This was a violent attack in which the victim received life-changing injuries to his face caused by a Stanely knife.
“Thankfully local bar staff came to his aid and due to our night safe radio system a description was put out and a man was detained in George Street shortly after the attack.
“We are in the early stages of the investigation and are trying to establish the exact circumstances that led up to the attack and would like to hear from any other witnesses who have not yet come forward.”
Anyone with information was asked to call Sussex Police on 101 or the independent charity Crimestoppers anonymously on 0800 555111.
A 28-year-old local man was arrested on suspicion of assault causing grievous bodily harm and has been bailed until Tuesday 25 September pending further inquiries.