STOCKHOLM :Khabib Nurmagomedov called time on his mixed martial arts career following a second-round submission win over Justin Gaethje on Saturday, leaving his gloves in the centre of the octagon to fulfil a promise to his mother.

He wore down his opponent with his constant forward pressure before mounting Gaethje and locking him in a triangle choke that rendered the American unconscious to extend his record to 29 wins and no defeats.

Many questioned if he would have the heart for the fight against Gaethje following the death of his father Abdulmanap in July from complications caused by COVID-19 at the age of 57.

His father had schooled him in combat sports from an early age and was in his corner in Abu Dhabi in September 2019 when Khabib choked out Dustin Poirier, on that occasion using a rear naked choke in another successful title defence.

"I talked to my mother three days (ago). She didn't want me to go fight without (my) father, but I promised her it's going to be my last fight, and if I give my word, I have to follow this," an emotional Khabib said in the octagon.

"It was my last fight. I know only one thing I want from the UFC - you guys have to put me number one pound-for-pound fighter in the world, because I deserve this."

After a stunning run of 13 wins in eight years and a professional record featuring eight knockouts and 11 submission wins in his 29 victories, few would argue with the 32-year-old who has now left the cage for the last time.