Costa (13-1) lost to Adesanya (20-0) via second-round TKO on Yas Island in Abu Dhabi, United Arab Emirates. Adesanya finished the fight with punches in the center of the Octagon as Costa was turtled up in front of him. After the referee stepped in, Adesanya did not back away from Costa immediately and made several vulgar gestures toward him.
Costa, who flew to his native Brazil on Monday, expressed his anger on social media on Monday and demanded a second fight against Adesanya.
"I come here to talk about the actions that the human trash did after our fight," Costa said on Instagram. "I didn't see when I was there in the cage, but I saw now. I disapprove 100 percent. To me, this is mortal now. Nobody will stop me. Nobody can stop me. I want my rematch. You know I am waiting for you.
"Something happened before the fight. I'm not [making] excuses here to my people, to my fans, but I will be 100 percent to fight him and make him pay. That's my word. Save my words."
Adesanya, who also exchanged words with Costa's coach Eric Albarracin after the bout, has been unapologetic regarding his postfight celebration and has shared several posts about it on social media. There was plenty of prefight animosity between the two undefeated fighters going into UFC 253. Adesanya repeatedly called Costa "dumb" and accused him of using performance-enhancing drugs. Costa said he would "kill" Adesanya in the cage.