Two men were attacked with knives outside a Ponsonby bar in the early hours of Sunday morning when they tried to walk away from an argument with two others.
One of the offenders punched the man, while his acquaintance grabbed knives from a nearby car before attacking both men and leaving one of them with serious injuries.
A 21-year-old was taken to Auckland City Hospital with cuts to his face and head area, while the other man had a slice across the back of his hand.
Detective Senior Sergeant Glenn Baldwin said a group had been socialising at a bar on Mackelvie St.
The victims and the two men who were unknown went outside the Mackelvie Street bar started arguing.