Anthony Joshua challenges Daniel Dubois for the IBF world heavyweight title at Wembley Stadium on Saturday September 21, live on Sky Sports Box Office; Riyadh Season: Joshua vs Dubois also features Joshua Buatsi, Josh Kelly and Tyler Denny on a packed undercard

Vitali Klitschko is backing Anthony Joshua to defeat Daniel Dubois and become a three-time world heavyweight champion.

Klitschko is a legendary former champion, who held the WBC belt with distinction. Earlier in his career he fought Lennox Lewis, the last undisputed heavyweight champion before Oleksandr Usyk beat Tyson Fury in May of this year.

Unsupported locationThe video you are trying to watch cannot be viewed from your current country or locationBack in 2003, Lennox Lewis stopped Vitali Klitschko after a thrilling and bloody encounter in Los Angeles

Even under those circumstances, the former champion has been following the course today’s heavyweights have been charting through the division.

He’s seen improvements in Anthony Joshua.

Since his losses to Usyk, Joshua has brought in different training teams and gradually progressed through wins over Jermaine Franklin and Robert Helenius before dominating Otto Wallin and icing Francis Ngannou.

Klitschko’s verdict: “Sometimes a step back means you can take two or three steps forward and I hope Joshua learned a lot and will be well motivated in the next fight.”

The IBF world title that Usyk vacated is on the line in the Riyadh Season: Joshua vs Dubois event at Wembley Stadium, live on Sky Sports Box Office on September 21.

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Unsupported locationThe video you are trying to watch cannot be viewed from your current country or locationA look at Anthony Joshua’s journey so far ahead of his upcoming fight against Daniel Dubois

Klitschko is backing AJ for the win. “I keep my fingers crossed for Joshua. Good man. Good heart. Good sportsman and has good s𝓀𝒾𝓁𝓁s,” he told Sky Sports.

His brother Wladimir Klitschko, who’s own heavyweight championship reign ran concurrently with Vitali’s, headlined Wembley Stadium in an epic 2017 fight with Joshua.

He famously dropped Joshua in the sixth round. Vitali was in his brother’s corner and wonders if he could have changed boxing history if he’d told Wladimir to go for the knockout finish there and then.

Johnny Nelson discusses the heavyweight showdown between Daniel Dubois and Anthony Joshua and what Dubois will have to do during the fight to defeat AJ

“History doesn’t like the word if. If… Joshua is a good fighter. A fight is about physical condition,” he said.

“It’s about strategy and regarding the psychological game. In this fight Joshua was stronger than Wladimir.

“My personal opinion as a sportsman is Wladimir made a couple of mistakes. Wladimir was prepared great for the fight but if… If,” he added with a laugh.

Image:Anthony Joshua fights Daniel Dubois at Wembley Stadium live on Sky Sports Box Office on September 21

“For me this fight was very important. I’m much more quiet and comfortable when I am inside the ring.

“When I’m outside in the corner of my brother, I’m so nervous. It was a very difficult fight but it was a very interesting fight, a very interesting fight for the whole sports community, for all boxing fans.

“But in this fight Joshua was stronger than Wladimir.”