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For years, Conor McGregor and Khabib Nurmagomedov were bitter rivals. That was true in the lead-up to their fight, a lengthy period punctuated by McGregor throwing an equipment dolly into a bus carrying Nurmagomedov -- and half of the UFC 223 card in 2018. It was certainly true after Nurmagomedov beat McGregor at UFC 229 before both fighters' teams engaged in a wild post-fight brawl. And it has remained true for the years that followed, with McGregor calling for a rematch Nurmagomedov refused to give.

Following Nurmagomedov's dominant second-round submission of Justin Gaethje in the main event of UFC 254, and subsequent retirement, McGregor appeared to bury the hatchet with a single tweet.

"Good performance," McGregor tweeted. "I will carry on. Respect and condolences on your father again also. To you and family. Yours sincerely, The McGregors."

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Nurmagomedov had previously discussed retiring as lightweight champion with a 30-0 record. The Gaethje win ran his record to 29-0, but the death of his father earlier in the year and a promise to his mother led him to announce his retirement one fight ahead of schedule.

"Today, I want to say, this was my last fight," Nurmagomedov said after his victory. "No way am I going to come here without my father. It was first time, after what happened with my father, when UFC called me about Justin. I talk with my mother three days, she don't want that I go fight without father. I promised her, it's going to be my last fight, and if I give my word, I have to follow this. It was my last fight here."

McGregor is set to return to the Octagon after his most recent retirement. He will fight Dustin Poirier in January in a fight that could position the winner for a shot at the now-vacant lightweight title.