A 20-year-old Applecross man has been charged with grievous bodily harm after an alleged assault in Subiaco last night.
Police will allege he became involved in an argument with a 25-year-old man just before 11pm at a 21st birthday party on Hay Street.
A police spokesman said it appeared the 25-year-old was knocked out by a kick to the head while he was on the ground.
Officers arrested the younger man at the scene, while the alleged victim was taken to Sir Charles Gairdner Hospital with serious head and facial injuries.
The 20-year-old has been charged with GBH and is due to appear in the Perth Magistrates Court on Thursday, April 17.