Police said in a statement they were continuing their investigation into the incidents that saw one person arrested for assault and another for disorder.
"The victim, who is an Australian national, was taken to Middlemore Hospital. He has had to undergo surgery for facial injuries sustained in the assault," police said.
"A 46-year-old man was arrested at the stadium over the incident."
Police said they had not ruled out pressing charges.
Social media videos have surfaced of both sets of fans acting aggressively and insulting each other with security trying to intervene. Objects were also thrown and children were present in the Auckland FC seating block.
Auckland FC chief executive Nick Becker said in a statement that the club did not condone any form of anti-social behaviour.
"Auckland FC is extremely disappointed to hear of one or two isolated incidents of anti-social behaviour at Saturday's match involving the club and travelling fans from Western Sydney Wanderers.
"Auckland FC has worked extremely hard to cultivate a positive and inclusive family atmosphere for the 200,000+ football fans who have enjoyed an incredible season at Go Media Stadium. This includes our most passionate football fans, thousands of families and first-timers from Auckland, Wellington and beyond.
"This is the first time we have had any incidents involving fan anti-social behaviour and it's something that we take very seriously. It does not represent our values or who we are as a club.
"We are working closely with the police and the team at Go Media Stadium to see if any lessons can be learned, particularly in regard to how we manage travelling fans, as well as looking to identify and ban anyone who is found to be responsible."
The club boss said should fans need help or assistance at any point, to text the word "ASSIST" along with their seat number or location to 260, and the security team will be dispatched.
Director of Auckland Stadiums for Tātaki Auckland Unlimited, James Parkinson, said its on-site security worked with police to swiftly de-escalate the incidents, which also resulted in eight evictions.
"Saturday's isolated incidents are in sharp contrast with an overwhelmingly positive and respectful behaviour we have witnessed from fans throughout this football season."
"We will be reviewing these incidents and working closely with Auckland FC to implement agreed changes so the focus rightly returns to the football and the family-friendly environment fans have been enjoying all season," Parkinson said.
The A-League match between Auckland and the Western Sydney Wanderers ended 1-1.
Auckland remain top of the ladder with 46 points, five points ahead of Western United with four games left before the A-League finals.
