Floyd Mayweather announces unexpected fight against Japanese kickboxer Tenshin Nasukawa

Floyd Mayweather is searching for a new challenge. Photo / Photosport

In the wacky world of combat sports, nothing should come as a surprise.

And just as Conor McGregor stunned the world by agreeing to step in the ring with boxing legend Floyd Mayweather last year, now the American is making waves.

McGregor has continually baited Mayweather, daring him to take off the gloves and step in the Octagon. He's rebuffed the Irishman but is now linking up with MMA — though in exactly what capacity remains to be seen.

At a press conference in Tokyo today, the 41-year-old announced he will fight Japanese kickboxer Tenshin Nasukawa on December 31 in Saitama, about 30 minutes outside of the Japanese capital.

He will fight at the new year's event for the Rizin Fighting Federation, a Japanese MMA promotion founded in 2015.

Mayweather said the "weight class and rules" will be finalised in the coming weeks, refusing to confirm whether the bout will be under boxing or MMA rules.

Mayweather, undefeated across 50 fights, has never fought outside the US, making today's revelation even more astonishing.

Rizin CEO Nobuyuki Sakakibara reportedly said the MMA promotion was thrilled to have convinced Mayweather to take part in the "history-making event".

"First we had to convince Mr. Mayweather to come to the ring on the Rizin ring on December 31," he said. "As you know Mr. Mayweather is undefeated. But all his fights have been in the US. He has had a wish to fight outside the US.

"We're happy we've convinced him to come to Japan for this history-making event. In the second phase, once we knew Mr. Mayweather would be in the Rizin ring on New Year's Eve, we thought of the appropriate opponent and there was only one: Tenshin."

Understandably, the world was in shock over the surprise announcement.

We have to be living in the strangest time in combat sports history.

— Luke Thomas🏋️‍♀️ (@lthomasnews) November 5, 2018

Mayweather posed with MMA gloves on but I’d be shocked if this isn’t a boxing match. It should only count as an exhibition. https://t.co/pnHqjscGmW

— Ryan Songalia (@ryansongalia) November 5, 2018

Loooool mayweather is fighting a kickboxer in december whats going on

— Harry (@wroetoshaw) November 5, 2018

Mayweather hasn't fought since defeating McGregor by TKO in the 10th round last August. Many on social media speculated the ageing star is coming out of retirement purely for a cash grab.

Mayweather posted a photo on Instagram wearing Rizin gloves shortly before Monday's big reveal.

Nasukawa is reportedly unbeaten and is fresh off a victory over former UFC fighter Kyoji Horiguchi in a kickboxing match.