A man injured in a brawl in Papakura, south of Auckland, has had surgery and is in a serious condition.
Police say a fight broke out on Saturday night between about 11 people from two neighbouring houses. A party was being held at one of the houses.
Police initially said the 21-year-old was stabbed in the head, but later said he was hit with a heavy object.
A 21-year-old man has been arrested and charged with wounding with intent to cause grievous bodily harm.