Commonwealth heavyweight champion Joe Joyce will fight 6ft 7in Russian veteran Alexander Ustinov this month in preparation for his British title fight against Daniel Dubois in July.
Olympic silver medallist Joyce will take on the 42-year-old on the undercard of Billy Joe Saunders' WBO interim super-middleweight world title bout against Germany's Shefat Isufi in Stevenage on 18 May.
Joyce has won his eight professional bouts by knockout. Ustinov has won 34 of his 37 fights, 25 by knockout.
The Briton, 33, won the WBA Gold title in his last fight against former world champion Bermane Stiverne in February.
"I could have waited until the big fight night on July, but I wanted to keep busy," he said.
"I didn't want a journeyman, so we chose a giant and former world title challenger who's only lost three times. He is big, awkward and he can punch."