Floyd Mayweather floors Tenshin Nasukawa in first round three times to win exhibition

140 seconds was what Floyd Mayweather needed to beat Japanese kickboxer Tenshin Nasukawa in an exhibition boxing bout worth a reported $9m.

The 41-year-old former five-weight world champion Mayweather, was smiling during the short-lived contest in Tokyo as he floored the 20-year-old three times.

The bout, scheduled for three three-minute rounds, finished with Nasukawa in tears as his team threw in the towel.

Despite his latest comeback, Floyd Mayweather said afterwards he was "still retired".

"It was all about entertainment - we had a lot of fun," said the American, who beat UFC's Conor McGregor in a boxing match in August 2017. "They wanted this to happen in Japan, so I said 'why not?'"

The fight was delayed for several hours, with rumours spreading on social media that Mayweather might not show up, and that organisers were struggling to locate him.

Suddenly, an "unscheduled intermission", he promoted his Las Vegas strip club, urging people to go there to watch the event.

Both fighters remained undefeated coming into the widely criticised contest, in which Mayweather had a 4kg (9lb) weight advantage.

And after defeating Nasukawa, Mayweather insisted: "I'm still undefeated; Tenshin is still undefeated. Tenshin is a true champion and a hell of a fighter."

Addressing the Japanese fighter, he added: "Hold your head up high. "I want the fans around the world to support Tenshin, he's a great guy and a great champion."

The rules were very strictly defined with Nasukawa reportedly facing a $5m fine if he aimed a kick at his opponent.

There were no judges, with only a knockout or technical knockout considered a victory.

Before the fight, Amir Khan, the former light-welterweight world champion said the bout was a “joke” and was "hurting boxing".

Last year, Mayweather also came out of retirement to defeat McGregor in the Irishman's first ever boxing match.

That fight also received heavy criticisms as a mismatch prior to one of the richest contests in boxing history, but afterwards BBC Radio 5 live boxing commentator Mike Costello said McGregor had "proved the doubters wrong".