Khabib Nurmagomedov defeated Justin Gaethje in a second-round submission during UFC 254, Saturday. Following the fight, the unbeaten champion announced his retirement citing the loss of his father.

Khabib, Justin GaethjeHandout / Getty Images

"This is my last fight, there's no way I'm going to be back without my father," he told the audience. Nurmagomedov's father, Abdulmanap Nurmagomedov, passed away earlier this year after a battle with COVID-19.

While Gaethje proved a respectable opponent, firing off powerful leg kicks and staying aggressive throughout, it was Nurmagomedov who locked the challenger in a triangle choke in the 2nd round, rendering Gaethje unconscious, to secure the victory.

Nurmagomedov, head in his hands, collapsed in the center of the octagon following the fight. 

"I promised her, this was gonna be my last fight," Nurmagomedov said, recalling a conversation with his mother earlier this year. "If I give my word, I have to follow this."

Gaethje regained consciousness quickly, afterward. "I know he made his father so proud," he said. Gaethje began the day on a four-fight winning streak.

Nurmagomedov is now tied with BJ Penn and Benson Henderson with the most title defenses in UFC lightweight history. If this truly is his last fight, he will end his career 29-0.