The female warden, who voluntarily rides the train to help look after commuters, can be seen in the footage bravely placing herself between the two groups as one of those on the platform tries to board the train and another throws a kick through the doors.
Eventually the woman is assisted by others on the platform, allowing the train to close its doors and depart the station.
The train manager and the train's driver can also be seen trying to calm down those arguing and fighting.
Rail and Maritime Transport Union northern regional organiser Rudd Hughes praised the Māori Warden's bravery, saying she did a "great job".
"The train manager was also there and I think it would have been a lot worse if they weren't there, it would have been an all-in brawl," he said.
"It exemplifies why we believe the train managers are so crucial for safety and need to stay on there."
The incident comes as a dispute over whether train managers should be removed from the trains remains unresolved.
Currently, there is a train manager on every train.
However, earlier this year, the RMTU went on strike over pay and plans by Transdev, which operates the trains on behalf of Auckland Transport, to remove train managers from trains.
Transdev wanted to replace them with a smaller number of transport officers, who would not be on every train but would instead circulate between trains on the network.
In some cases, this would have left only drivers on the trains, said Hughes.
Following the union's strike this year, it agreed with Transdev and Auckland Transport to negotiate a resolution about the future of train managers, but this had yet to be fully agreed upon.
Hughes said that at the moment, this meant some Auckland trains may have a train manager, transport officer and Māori Warden on board.
