As it was a pre-season match, both teams agreed Queens Park would be allowed to replace the red-carded player to maintain an 11-a-side contest, the spectator said.
When another scuffle broke out between the teams, the red-carded player returned to the pitch before being ordered off for a second time.
While the game progressed again, things were starting to get "a little niggly", the spectator said.
"Then there was yet another foul and things sort of went a bit nuts from there as everyone dived in and there was pushing and shoving and some punches thrown."
The red-carded player was again in the thick of the action, and knocked out the Queenstown goalkeeper with a punch, the spectator said.
Posts on social media alleged another player was kicked while on the ground, and there were calls for life bans.
Queens Park AFC president Leeann Duston said in a statement that Saturday's events were under investigation by the club which was following the correct disciplinary paths.
It would not be able to comment further on the brawl until it had received the official match report from the referee, but there would be heavy suspension consequences for any players found to be involved.
Queenstown AFC did not respond to requests for comment yesterday.
Football South chief executive Dougal McGowan was not aware of the incident when spoken to yesterday afternoon.
He said the referee's report would go to the organisation's competitions team, and would be followed up this morning.