An unprovoked attack left a 50-year-old man with a fractured eye socket.
The victim was walking in St James’s Street, Brighton, at about 2am on Friday (8 August) when he was approached by a man who asked him for a cigarette.
Without warning, the attacker then punched the victim and ran off along St James’s Street.
The attacker was described as white, about 30 years old and 5ft 6in tall with scruffy brown hair.
Detective Constable Melanie Wauchope said: “This was a nasty attack in an area of the city that could have had quite a few people in it at that time on Friday night.
“I need to speak to anyone who saw the attack or the man running away. Any information at all that you have could be useful so please contact us.”
Anyone with information is asked to phone Sussex Police on 101, email 101@sussex.pnn.police.uk or call the independent charity Crimestoppers anonymously on 0800 555111.