Russian Murat Gassiev retained the WBO heavyweight title after knocking out German Peter Kadiru in the sixth round of their bout on Saturday in Moscow, the Russian capital. Kadiru's corner threw in the towel, ending the fight at the VTB Arena after the German was caught in a series of consecutive punches while trapped against the ropes, bringing Gassiev's record to 34 wins against 2 losses and retaining the title for the first time. The German, who suffered his second defeat in 25 fights, was a replacement for French boxer Tony Yoka, who withdrew days earlier due to a back injury. Gassiev (32 years old) won the WBO title last December after defeating Bulgarian Kubrat Pulev, and currently tops the heavyweight rankings following Ukrainian Oleksandr Usyk's relinquishment of his world titles, which led to a reshuffle in the competition for titles in this division.