41-year-old Floyd Mayweather came out of retirement briefly to fight Japanese kickboxer Tenshin Nasukawa in an exhibition boxing match and win the easiest $9m in his entire career.

20-year-old Nasukawa is unbeaten in professional kickboxing and mixed martial arts. In the first round against Mayweather, however, he was sent crashing to the canvas three times in 120 seconds forcing his corner to throw in the towel.

Although Tenshin connected with one early shot, he offered no real resistance as Mayweather used all his guile and enormous power to rip shots to the body and head at will.

After the match, Mayweather said:

“I want to say thank you to Tenshin. This don’t go on our record,” the American fighter said before dismissing speculation surrounding a return to professional boxing.

“We are both still undefeated. He is a great champion and a great fighter. I am still retired, I don’t look to come back to boxing.

“I came back for entertainment for the people of Japan.”

Mayweather had in an Instagram post suggested that he would be paid $9m for the fight, which was scheduled for three rounds.

There were no judges in attendance and the fight does not count toward the professional record of either fighter.