Watch: Massive street brawl breaks out during the UFC broadcast

A teenage boy has been hospitalised with a fractured eye socket after 50 UFC fans started brawling outside a Sydney hotel.

The brawl broke out during the UFC fight between Connor McGregor and Nate Diaz and spilled out onto the street outside the Ritz Hotel in Hurstville, south of Sydney, on Sunday at about 5pm.

The massive fight, which involved up to 50 people, is believed to have started with an argument inside the hotel during the UFC broadcast.

Footage of the brawl shows people sprawled on the street as groups of people continue fighting.

Two 17-year-old boys were found by police with injuries. One of the boys was taken to St George Hospital to be treated for a fractured eye socket.

The other boy was found to be suffering bruising to his forehead.

The only person arrested so far is a 15-year-old girl who was using offensive language.

Police say she was taken to Hurstville Police Station where she was later released and is expected to receive a youth caution.

No arrests have been made in relation to the assault of the males, however inquiries are continuing.