Groups of supporters of both rival nations were out in force in the suburb of Otahuhu during the Rugby League World Cup, and when they clashed the fight was captured on video.
It shows two groups brawling in the middle of the road as cars drive past honking their horns.
Police confirmed the incident on Tuesday night and said the four people arrested were Tongan supporters.
Counties Manukau West Area Commander Inspector Naila Hassan urged fans to behave responsibly.
"Overall supporters have been well behaved, however the actions of a small number of people have been disappointing."
She said police wanted fans to enjoy the tournament and show respect for others.
Reckless driving had been another concern for police.
"We've had a few reports of people leaning out of cars or sitting on car bonnets. This risky behaviour is not only illegal but very dangerous."
Hassan said police were patrolling the area to ensure people were behaving responsibly
League rivals Tonga and Samoa meet in their World Cup clash in Hamilton on Saturday.
Gold Coast Titans league player Konrad Hurrell posted a video on his Facebook page of the Tongan team appealing to their fans to behave.
In the video team captain Sika Manu said they're all from the islands, and asked fans to keep the peace.
Tongan star Tui Lolohea said: "It's a bit rude to see, you know.
"At the end of the day, it's just a sport between two nations who are pretty passionate about their sport.
"It's pretty embarrassing to see that kind of stuff. It's a game of footy, so the boys kind of leave that stuff for the field, and I guess it's just more for the fans to enjoy. So hopefully we can get some peace going on, and we can all unite as one and keep it together."
His Tongan team-mate Solomone Kata said: "To be honest, I don't know what they're thinking out there.
"But us players, us Tongans, we don't have a hard feeling for the Samoan team. We just play the game, and even if something happens on the field, it just stays on the field, we just walk around off the field as a brother, as one."
The Tongan league team was greeted by jubilant fans when they touched in Auckland on Tuesday ahead of their first New Zealand match in the Rugby League World Cup.