The brawl came after days of heightened tension between Samoan and Tongan rugby league fans, ahead of their second round World Cup clash in Hamilton on Saturday.
Police say a crowd of up to 200 Samoan and Tongan fans gathered in a carpark near the Manukau Institute of Technology in Otara last night.
"It was major disorder", said Superintendent Sandra Manderson, the police national commander for major sporting events.
"Some people in the crowd were carrying poles and sticks... I believe there was also a machete taken off someone."