Police are appealing for witnesses after a gang of teenagers attacked the 24-year-old at about 12.30am on Saturday August 17.
The couple were walking in South Street, Tarring, at the entrance to Tarring recreation ground when they were approached by a teenager from a group of about a dozen youths.
The teenager punched the victim in the face before the rest of the gang joined in, punching and kicking the victim to the ground and then running off.
The male suffered bruising to his face, a chipped tooth and a cut underneath his eye which needed treatment at Worthing Hospital.
The main attacker was white, between 16 and 18, 6ft and thin. He had short fair hair which was thinning, had eyes that were very close together and was clean shaven.
He was wearing a hooded top with a centre zip, trousers and trainers.
PC Alexandra Watt, from Worthing Response Investigation Team, said: “This was an unprovoked attack which could have resulted in a more serious injury to the victim.
“We are keen to speak to anyone who saw the attack take place or who knows who is responsible.”
Anyone with information should call 101 quoting serial 61 of 17 August or the independent charity Crimestoppers anonymously on 0800 555111.