A 30-year-old man suffered a fractured jaw after he was the victim of an unprovoked attack in Northampton town centre.
The man was outside a kebab shop on the corner of Gold Street and Horsemarket at 5.15am on Sunday and was punched in the face.
The victim required hospital treatment for a fractured jaw.
The offender is described as a white man, 5ft 8in, aged about 25 with a slight build and light brown hair. He was wearing a light brown or grey T-shirt.
Witnesses to this incident, or anyone with information, can call Northamptonshire Police on 101 - alternatively, information can be given anonymously to Crimestoppers on 0800 555 111.