St George police are investigating a brawl at a Riverwood reception centre on Sunday.
About 12am a fight broke out between 25-30 people outside the Belmore Road centre, which was hosting a wedding reception.
When police arrived they found a man, 22, semi conscious with mouth and nose injuries.
One bystander, who did not want to be identified for her own safety, said it was an ugly scene.
“A whole group of men seemed to gang up on one man and he was on the floor and they were kicking him and punching him,” she said.
“It seemed like more and more people joined the big crowd.
“There were women in hysterics and screaming and trying to pull the men apart.”
Police said witnesses on the scene were uncooperative so they have put out a public plea for information.
They have seized security footage from the function centre as investigations continue.
Anyone with information should contact St George police or Crime Stoppers on 1800 333 000.