Investigators are appealing for witnesses after the fight.
A man was left with a head injury after being 'repeatedly struck around the head with the buckle of a trouser belt', Sussex Police has said.
Investigators are appealing for witnesses after the fight at 2am on Sunday (November 13) in Ship Street, Brighton, which reportedly started outside the Seven Stars pub.
Police said: "A 36-year-old Dover man who was visiting the city with friends, was repeatedly struck around the head with the buckle of a trouser belt that another man had taken off.
"The victim sustained a cut head and was treated at the Royal Sussex County Hospital before being discharged.
"A 46-yea- old Saltdean man was arrested on suspicion of causing actual bodily harm and after being interviewed was released on police bail until January 7 while enquiries continue."
Detective Constable Leon Howe said: "The alleged assailant is described as being in his mid-forties, short, of muscular build, of Eastern European appearance, and wearing dark clothing."
Anyone with information should contact police by calling 101, emailing email@example.com, or by going online, at sussex.police.uk/contact-us/response-to-appeal. The crime reference number for the incident is 0127 of 13/11.