Queenstown police have charged a 23-year-old man over an alleged "one-punch'' assault in the CBD, while they hunt for a second man believed to be involved.
Sergeant Steve Watt said the 23-year-old man's friend pushed a stranger, who was walking past the pair, to the ground about 1am on Saturday in the mall.
As the victim tried to get off the floor, he was allegedly punched in the back of the head and knocked unconscious by the 23-year-old, Sgt Watt said.
St John spokesman Gerard Campbell said the man was taken to Lakes District Hospital with minor injuries.
The two offenders ran from the scene.
Police located the man who is accused of throwing the punch, but were still looking his friend.
The incident was likely to be on CCTV footage, Sgt Watt said.
A shirtless Brazilian man allegedly hit an Alexandra woman in the face as she walked past him outside a bar in Church St about 1am on Sunday.
The woman's friend, who is also from Alexandra, then got into an altercation with the man and the situation escalated when police tried to break up the argument, Sgt Watt explained.
The woman then allegedly punched the man who hit her, while her friend allegedly punched him in the ribs.
Police charged the man and the Alexandra woman with common assault.
The man who allegedly instigated the fight was arrested for assault and obstruction, while a second Brazilian national was arrested for disorder and possession of cannabis.
About the same time, another fight broke out between three English backpackers, who had been travelling in a camper van together.
The incident happened in Camp St, outside O'Connell's Pavilion.
Members of the public stopped the fight, and police issued two of the men with a pre-charge warning.