A Sydney man has described the moment he and his family were set upon by a group of while celebrating a young child’s birthday party.

Three men were treated in hospital after the brawl erupted between men celebrating separate birthdays at Lollipops Playland and Café in Wetherill Park yesterday.

The melee was reportedly sparked after a seven-year-old girl allegedly had her hair pulled and was threatened by a man in a dispute over play equipment.

A man who wished only to be referred to as “Chris” said his father and a friend became reluctant participants when they approached the man responsible.

“A person grabbed me and I said, ‘mate I don't want to fight, just don't touch me’,” he told 9NEWS.

“They've pulled my hoodie and they've started attacking me, and they've punched me and dropped me on to the floor.

“They were jumping on my head and stepping all over me.”

Chris said he feared for his life as he was set upon.

“I was just saying to myself, you know, protect yourself, don't get knocked out because if you get knocked out you're pretty much going to die,” he said.

The managing director of Lollipops Playland said he was lost for words over the patrons actions.

“Their behaviour is absolutely shocking,” Tim Newman-Morris said.

“Anyone who thinks it's acceptable in a children's playland is...

“I don't know what to say to be honest.”

A video of the fight shows children hiding in play equipment and screaming as men throw punches wildly and a man on the floor has his head stomped on.

Amidst the madness, the seven-year-old girl called triple zero to alert them to the brawl.

The attackers fled in their cars after the alleged assault.