Just Stop Oil protesters forced a stoppage in play during the English rugby union premiership final at Twickenham.
Two men invaded the pitch midway through the first half of the match between Saracens and Sale, throwing orange paint powder on to the field.
Twickenham Stadium in London later confirmed two men had been arrested and that the incident is now a police matter.
Fans jeered the duo before cheering as stewards escorted them from the stadium.
Orange powder remained on the field as the match resumed.
A statement from Just Stop Oil said the men involved in the protest were Dr Patrick Hart (37), a GP from Bristol and Sam Johnson (40), a construction worker from Essex.
“Two Just Stop Oil supporters have disrupted the Gallagher Premiership Rugby final,” read the statement.
“They are demanding a halt to any new licences for oil, gas and coal projects in the UK.”
The statement also outlined the pair’s reasons for taking part.
Hart said: “I am doing this because it’s my duty as a doctor. The climate crisis is the greatest health crisis humanity has ever faced.
“People are dying now and more will die every day unless we stop new oil, gas and coal.
“In the same way the tobacco companies lied to us that tobacco was safe, the scrum of fossil fuel companies and corrupt politicians have been lying to us. They are keeping us addicted to fossil fuels, even though they know it’s killing us.
“I am not prepared to let them get away with mass murder. We are ordinary people. We are the doctors and nurses who care for you when you are sick. I call on everyone to come and join us in the streets and be on the right side of history.”
Johnson said: “I took action today simply because we have run out of time. We’ve got to tackle this now.
“We have known for longer than I’ve been alive what would happen if we kept burning fossil fuels and now we are seeing this catastrophe unfold in real time. The whole world knows that licensing new fossil fuel projects in 2023 will cause the deaths of millions of people.
“We are at the greatest crossroads humanity has ever faced and unless we act now we will lose everything we have ever cared about. I have a nephew who is seven years old, who I love to bits, and as long as I have breath in my lungs I will fight to protect his future.”
A statement from Twickenham Stadium read: “Twickenham Stadium can confirm two people have been arrested and this is now a police matter.
“We would like to thank our stewarding team who acted decisively and swiftly.”
The protest followed a similar one at the World Snooker Championship in April.
On that occasion, a man tipped orange paint on the table during the match between Robert Milkins and Joe Perry at the Crucible in Sheffield.
A woman was prevented from executing a similar stunt on the other table after being tackled by quick-thinking referee Olivier Marteel.