Sergeant Keith Newell said the victim, a 34-year-old Brazilian national who resides in Queenstown, was attacked outside Bungalow, in Camp St, at 4am.
''He's been pushed to the ground and punched about seven times to the head.''
The man was not seriously injured and did not require medical treatment.
Sgt Newell said the incident was captured on CCTV and police were still looking for the alleged offender.
He was believed to be a French national, about 25 years old, and was with a group of six or seven males and one female.
Police also wanted to speak to any witnesses to the assault, in which alcohol ''was a factor''.
''We're getting a wee bit concerned about the number of early morning assaults, which are usually alcohol-related,'' Sgt Newell said.
On Tuesday, the Otago Daily Times reported Queenstown police were investigating another alleged assault after a man was punched in the face while trying to intervene in an argument between a couple in Camp St about 1.30am on Sunday.
Police responded to a family harm incident in Redcastle Rd, Oamaru, about 3pm on Monday. A 22-year-old Oamaru man was arrested and charged with assault. He is due to appear in the Oamaru District Court on August 29.
