Nurmagomedov, meanwhile, retired from the sport in 2020 as the reigning UFC lightweight champion. "The Eagle" went 29-0 over the course of a career that began in 2008.

"Had a rough night last night as I expected," Khabib Nurmagomedov wrote on Instagram. "Islam Makhachev has once again proven that he is the best in the world right now, and I am very happy for him ...

Buckley explains why he thinks Nurmagomedov never moved up to welterweight. "Khabib was smart, though," Buckley said. "He knew he couldn't handle guys at 170 (pounds).