Khabib Nurmagomedov sent shockwaves through the MMA world Saturday, announcing his retirement after a submission win over Justin Gaethje in the UFC 254 main event.

Nurmagomedov retained the lightweight title against Gaethje - who held the interim title - in the second round in Abu Dhabi, United Arab Emirates. The stoppage came at 1:34.

"It was my last fight," he said in his postfight interview. "No way am I going to come here without my father ... I promised (my mother) it's going to be my last fight.

"One thing I want from the UFC on Tuesday: you guys have to put me on the No. 1 pound-for-pound fighter in the world. I deserve this."

Early in the second round, Nurmagomedov took Gaethje down and immediately established full mount. He reversed to a triangle choke and forced Gaethje to tap out. The referee didn't immediately see Gaethje tap and the challenger went out cold.

Nurmagomedov's pace was frantic in the opening frame. The champion marched Gaethje down, trying to get the 31-year-old to the mat and attacking him with strikes.

Gaethje got in a few shots, too, landing solid punches as Nurmagomedov walked forward. He also used his patented leg kick to attack the champion.

Nurmagomedov extended his pro MMA record to 29-0 with the victory. This was his third title defense.

Gaethje saw his four-fight winning streak come to an end with the loss.