Anthony Joshua has admitted “I let myself down” after the British heavyweight’s antics following his crushing defeat to Oleksandr Usyk in their world-title showdown in Saudi Arabia were heavily criticised. Writing on Twitter, Joshua hailed Usyk as “a class act”, adding: “Yesterday I had to mentally take myself into a dark place to compete for the championship belts! “I had two fights, one with Usyk and one with my emotions, and both got the better of me. “I’ll be the first to admit, I let myself down. I acted out of pure passion and emotion and when not controlled it ain’t great.