IBF, IBO, WBA, WBO heavyweight champion Anthony Joshua was eager to sit ringside this past Saturday night at the SSE Arena in London.

He watched Oleksandr Usyk win a tough twelve round unanimous decision over Derek Chisora.

Usyk , who took part in his second fight at the weight, is the WBO's mandatory challenger to the Joshua.

While Joshua was there to support Chisora, he was also there to get a live view of Usyk.

Joshua has studied some of Usyk's fights on tape - but said it was refreshing to see him in a heavyweight fight up close.

"I need to see my competition in the flesh," Joshua told Sky Sports News.

"I'm in my own training camp but it's a good time for me to learn what else is out there. It's a business opportunity. I want to come down and see what my competition is doing. As much as it is to support Derek, it is to see how good my mandatory challenger will be."

Joshua will defend his world titles on December 12, when he takes on IBF mandatory challenger Kubrat Pulev.

If Joshua wins, he wants to face WBC champion Tyson Fury in a full division unification in 2021.

But, Usyk wants his mandatory shot before that mega-contest happens.

"I am the mandatory for Joshua so he has two options," Usyk told Sky Sports News.

"One; to fight me. Two; to vacate and to go and fight Fury. Either he fights me or relinquishes. I am waiting. I am ready."

Usyk and Joshua both captured gold medals at the 2012 Olympic games. Usyk turned pro at cruiserweight and unified the entire division in 2018, which led to his decision to move up in weight to pursue more world titles in boxing's biggest weight class.