The bar owner told the Herald he could confirm the fight happened at the top of the street outside Hollywood bakery and involved two groups.
"The fight started after closing time. Two of my doormen went up to break up the fight when they saw what was happening.
"Looks like one person got knocked unconscious and another person realised after the fact that they were bleeding, possibly from being stabbed or cut by a bottle.
"No knife or broken bottle had been recovered from the scene at that time."
The incident was one of a number of disorder incidents in the central city overnight, including a man being hit by another man on Fort St, police said.
A 26-year-old man is due to appear in the Auckland District Court on Fridaycharged with assaults with intent to injure, as a result of that incident.
The victim of the assault was in a serious condition in hospital.
"While police staff were kept busy overnight, we had anticipated there would be increased numbers of people in the central city this weekend," the police spokesperson said.
A St John Ambulance spokesperson said one person was seriously hurt and two were in a moderate condition after incidents early this morning.