A protester set his arm alight at the Laver Cup tennis tournament at the 02 Arena.
The man screamed in agony in front of stunned spectators who saw him storm on court and sit down before flames shot from his arm on Friday.
Stunned onlookers watched on as the man, believed to be a climate protester called Kai, stormed the court before sitting down by the net.
He then sat completely still as security charged towards the scene before apprehending him.
The 20 year-old is a member of the End UK Private Jets group, which claims that ‘carbon emissions in 2022 are genocide’.
Previously another demonstrator tied themselves to the net during the French Open semi-final between Casper Ruud and Marin Cilic.
A video was posted on Twitter by End UK Private Jets immediately after the stunt of Kai explaining why he was going to set his arm on fire.
He said: “In a few hours time I’m going to go to the Laver Cup tennis tournament and set my arm on fire on the court.
“People are gonna say stuff like ‘this is horrible’, people in the stadium are going to be disturbed, and anyone who hears about it is going to be really traumatised, especially if they’ve had experiences with things like self harm.
“Feelings of anger about this... I think it’s right to feel anger about that because it’s unjust, people experiencing suffering.
“Humanity should have a responsibility to stop that sort of s*** happening, no one deserves to experience suffering, especially not young and vulnerable people.
“If we truly believe that... the way we act like that’s true is by stopping the climate emergency as fast as possible.
“Because right now we’re on a path where hundreds of millions of people are going through unimaginable suffering which is social collapse, torture, starvation, drought and war and s*** like that.”
The protest was opening day of the Laver Cup which runs at London’s O2 Arena until Sunday.
The tournament sees Team Europe take on The World in a major tennis bonanza.
It will be Roger Federer’s last ATP event since announcing his impending retirement from the game.
He has teamed up with career rival Rafael Nadal to take on Americans Francis Tiafoe and Jack Sock in a men’s doubles clash tonight.