Former two-time heavyweight champion Anthony Joshua recently reflected on his career and tabbed a Ukrainian boxer as being his toughest opponent to date.

But it wasn't Oleksandr Usyk.

Joshua said Usyk's countryman, Wladimir Klitschko, was his toughest foe in the ring.

Back in 2017, Joshua secured his career defining win with an eleventh round stoppage of Klitschko. It was a unexpected war where both boxers were on the floor. The end came when Joshua scored two knockdowns to stop Klitschko in round eleven. A massive crowd of 90,000 packed Wembley Stadium in London to watch the action unfold.

It was the final fight for Klitschko, who retired from boxing later that year.

Last September, Joshua was outboxed over twelve rounds by Usyk, who walked away with the IBF, IBO, WBA, WBO heavyweight belts.

"The hardest opponent I have come up against would be Wladimir Klitschko definitely," Joshua said during a Q&A with Oxford Union. "The passing of the guard. The young lion vs the old lion. At the time I fought him I thought it was definitely too early but it was his last fight.

"So if I didn't fight him then it would have been too late, so it was risk vs reward and I thought boxing needed it. Sometimes due to a lack of experience we make it harder than it sometimes need to be. He had definitely more knockouts on his record than I have fights and knockouts combined. He is experienced and very strong and it was a tough fight. Before that stage I was knocking guys out within six rounds and seven rounds. Wladimir took me eleven rounds somewhere I had never been before but he was my toughest for sure."

A rematch with Uysk is targeted for July 23rd in the Middle East. Joshua was stopped by Andy Ruiz in 2019, but bounced back with a wide decision in their rematch six months later.