A night of cage fighting in Greenwich had to shut down early - after members of the crowd started brawling with each other.
Thousands of spectators had packed into the IndigO2 on Saturday (March 15) for MMA Fury - a seven-hour mixed martial arts event with a bill of top semi-pro and professional fighters from around the world.
Tickets for the event - which had moved to the "bigger and sexier" Greenwich venue to boost seating and improve the production - had gone for £30.
But, with an hour still left to go on the bill, the event was halted at around 11pm after violence broke out in the stalls.
Fans and fighters alike reacted with anger to their fellow spectators' actions. Twitter user RoxiLloydxxx wrote: "Stood there for 6hrs last night.. friend was on in 2fights and they shut it down! F*****g p****s ruin it for everyone."
Thai boxer Rob Hayward said: "Disgusting what happened at Fury MMA last night. Everyone's dedication and hard work ruined because of idiots in the f*****g crowd."
Event organiser Stephen Doran said the fight had been "small" and the venue management had decided to shut it down.
He said: "It's a bitter thing for the sport because any event, whether it's a music event or something else runs the risk with alcohol being served.
"As mixed martial arts we're under so much more scrutiny than other people.
"We've been running it for four years and this is the first time something like this has happened."
Mr Doran added that they would put measures in place to stop problems at future events and said disappointed spectators would be able to get refunds from their ticket providers.
A spokesman for AEG Live, which runs the venue, said: "In the interest of public safety the 'MMA Fury' event at IndigO2 was closed early. We apologise for any inconvenience caused."