The incident occurred at the Studio Event Theatre on King Street, on Nov. 20, 2013, just hours after Brazil beat Chile 2-1 in a friendly match that had taken place in Toronto.
According to police, a 32-year-old man and his girlfriend were out celebrating the win.
While the couple was at the venue, another woman fell over and that woman’s boyfriend believed she had fallen after being assaulted by the 32-year-old man.
Police say that the suspect "violently confronted" the 32-year-old man, struck him and then kicked him in the head once he was on the ground.
The victim suffered life-threatening injuries, while the suspect left the scene in a vehicle with a group of other people.
Police say the suspect is between 5 feet eight inches and five feet 10 inches in height, with a thin build and he speaks French. He has been described as being Chilean, or South American, and he wore a blue and white, varsity-type jacket with the words "MMXIII THE BILLIONAIRE BOYS CLUB" on the back.
Police have released security video of the suspect, which can be viewed below:
The suspect may be from the Montreal area, police say.
Anyone with information is asked to contact police at 416-808-5200, or to contact Crime Stoppers at 416-222-8477.
Police say that they can put tipsters in touch with French- or Spanish-speaking officers, if desired.