Dustin Poirier pledged $20,000 to a charity of Charles Oliveira's choice just seconds after losing their world title fight.
Poirier is known as one of the most charitable fighters in the world, and was near tears after missing out on the UFC lightweight title for the second time in his career when he made the offer.
He had started well against Oliveira, dominating the opening round of their UFC 269 main event at the T-Mobile Arena in Las Vegas.
But when Oliveira took the fight to the ground in the second, it was the beginning of the end for Poirier, and he was finished within minutes of the third via a rear-naked choke.
Immediately following the bout, the pair embraced with Poirier offering to help out a charity in Oliveira's Brazilian hometown of Guaruja in Sao Paolo.
When Oliveira praised Poirier for "helping the kids" with his charity the Good Fight Foundation, Poirier made the generous offer, saying: "I would like to donate $20,000 to your hometown where you're from.
"I want to support the kids, you pick where the money goes - congratulations, I'm proud of you."
Oliveira grew up in a very poor part of the Brazilian tourist town, with his parents struggling to make ends meet.
It was there he learned to be a fighter, and developed the hunger that would take him to the pinnacle of combat sports.
And Poirier said that a video he saw before the fight where Oliveira discussed his upbringing inspired him to make the sizeable donation.
"I saw a video this week of him showing where he grew up and where his mom cooked dinner for him," Poirier explained at the post-fight press conference. "I think it was an old video.
"I saw some of the sights of where he grew up and just how little they had, it came to me this week.
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"I thought I was going to let him know win, lose or draw, talk to him after and let him know me and the Good Fight Foundation would donate $20,000 to his city in Brazil and put the money to wherever he thinks it needs to be.
"He's a good guy and he knows where the money will go the furthest, that's what we're going to do.
"And like I said, man, I'm going to continue to try to do good and that's it. I want to be a better person every day."
Poirier will now have to assess what is next for his career after once again failing to pick up undisputed gold in the lightweight division.
He has flirted with a move to welterweight, where an unprecedented fourth fight with Conor McGregor could become a reality, as well as a grudge showdown with Colby Covington.
But he has said that he will know early next week, with no guarantees as yet regarding where he will end up.
