Police are hunting for a group of gatecrashers who entered a birthday party in Matraville last night and stomped on the head of a 16-year-old boy.
Around six to eight uninvited males arrived at a 16th birthday party on Jennings Street at 10.40pm.
A 59-year-old male occupant of the house was punched in the face when he asked the group to leave and a 32-year-old man working as a private security guard was also punched.
A 16-year-old boy, who was a guest at the party, was then punched in the back of his head and, once on the ground, his head and neck were stomped on.
The gatecrashers then fled the scene.
The boy is currently in a serious but stable condition in the intensive care unit of St Vincent's Hospital.
Inspector Aaron Wunderlich said police at this stage do not believe the gatecrashers knew the estimated 40 guests at the party.
Mr Wunderlich said one of the suspects is in his early 20s, of middle eastern appearance and 175 centimetres tall.
Anyone with information relating to the incident has been asked to come forward to Crime Stoppers.
Police have also urged people preparing to host a party to register the event so patrols can be carried out and police can check in on the party.