Three men were treated in hospital after the brawl erupted between men celebrating separate children's birthdays at Lollipops Playland at Wetherill Park in Sydney on Saturday.
The brawl reportedly started after a seven-year-old girl allegedly had her hair pulled by a grown man.
The girl’s Dad told the Daily Telegraph he was knocked to the ground when he tried to intervene.
"I was on the ground and they pulled my shirt over my head and they were kicking me and punching me. I was just saying to myself ‘get off the floor, if these guys knock me out, I’m going to be dead here’," he said.
“We couldn’t compute it. We’re not aggressive people. But these guys were ruthless, they were just battering us."
Paramedics were called and took the men to Fairfield Hospital for treatment of injuries to the face, head, back, and hands.
Police are yet to lay any charges, and are urging anyone with information to call Crime Stoppers.