Former five division world champion Floyd Mayweather was a surprise guest on Saturday night at SSE Arena at Wembley, as he watched Anthony Joshua retain the IBF, IBO, WBA, WBO heavyweight titles with a knockout of mandatory challenger Kubrat Pulev.

For Joshua, it was his first bout since reclaiming his heavyweight titles with a dominant decision over Andy Ruiz last December in Saudi Arabia.

"What can I say, this is the fight game, at the same time I’m not in competition with anyone apart from myself," Joshua said.

"I’m staying true to myself, learning every day, I get older, I get wiser, I learn that this boxing game is chess and not checkers. I play a smart game and I make the right moves at the right time. Round nine, I got the knockout and onto the next."

Mayweather made headlines earlier this month, when the 43-year-old retired fighter announced that he was going to face Youtube star Logan Paul in an exhibition fight on February 20.

The one-time pound-for-pound king is a very big fan of Joshua's work.

"It’s always good to see some great boxing," Mayweather told Sky Sports .

"The UK is a great place, so many great fighters. I am proud of Anthony Joshua, and it’s lights, camera, action.

"He is one of the best heavyweights out there. Got a gold medal before. His career is going great, he is a hell of a fighter.

"Anything can happen in the sport of boxing, one shot can change it all. He is a great fighter, hell of a guy a gentleman and I respect his craft."