Nurmagomedov stops Gaethje, announces retirement at UFC 254

Khabib Nurmagomedov, right, announced his retirement Saturday after defeating Justin Gaethje at UFC 254. (AP Photo/Mahmoud Khaled, File)

ABU DHABI, United Arab Emirates — Unbeaten lightweight champion Khabib Nurmagomedov retired from mixed martial arts after stopping Justin Gaethje with a triangle choke early in the second round at UFC 254 on Saturday night.