Footage of the incident at the end of an amateur soccer match in Sydney on Friday night showed a sideline argument and a spectator shouting "hey ref, get out of there" before the adult official was felled.
The attacker, allegedly a suspended player, punched the referee's face at least three times and appeared to kick him before a dozen people rushed in to separate the pair.
After being moved away, the younger man made a second run at the injured referee, arming himself with a plastic chair, but was intercepted by players and others on the sideline.
"He broke my jaw, he broke my jaw," the bloodied referee says as other players assist him.
He was later taken to hospital. Bankstown police were investigating, a police spokesman confirmed on Sunday.
The incident, at the end of a men's match between Greenacre Eagles and Padstow Hornets, led the Eagles to withdraw from all remaining men's premier league matches in the 2023 season.
Its club committee pledged on Sunday to assist police and work with the association to impose appropriate sanctions.
"(We) reaffirm out position that all forms of violence have no place in our game and will continue to deal with such instances with the utmost seriousness," the committee said.
NSW Sports Minister Steve Kamper, a former president of Sydney Olympic Football Club, said the attack was "absolutely unacceptable".
"All referees and all players should feel safe wherever they're participating in local sport," he told reporters.
Premier Chris Minns noted the critical role that officials, often young, have in the success of amateur sporting organisations.
"It's appalling to hear," he told reporters.
"You cannot run these leagues that entertain, give our kids an opportunity to play as part of a team, get out of the house and play a team sport, unless people - often young people - agree to be referees in those games," he said.
Bankstown District Amateur Football Association said it would follow its judiciary regulations and processes, and reiterated its zero-tolerance policy to any form of violence at sanctioned events.
It was being supported by governing body Football NSW.
"Football NSW has zero tolerance for any antisocial behaviour from any of its participants at any time," Football NSW said.
