A female police officer was knocked unconscious by a man in the Ōtāhuhu town centre in South Auckland last night.
Police said she was hit from behind while dealing with disorder after the Tonga-Lebanon rugby league match.
An area was set up along Great South Road for fans to watch the match being played in Christchurch, as part of the Rugby League World Cup.
The zone was an attempt to stop a repeat of the mass disorder from fans last week where 53 people were arrested for disorderly behaviour.
Last night, 11 people were arrested in the Ōtāhuhu town centre following the rugby league game between Tonga and Lebanon.
Police said 10 arrests were for disorderly behaviour and one for carrying a weapon.
They said the incidents did not occur in the fan-zone, which was set up along Great South Road, but in side streets close by.
Police inspector Rod Honan said the officer had now been discharged from hospital and they were still looking for the person responsible for the assault.