Enzo Maccarinelli beat Roy Jones Jr with a devastating fourth-round knockout at the VTB Arena in Moscow.
The 35-year-old got the better of the opening two rounds against the 46-year-old Jones Jr, who is now a Russian citizen.
Maccarinelli did not have it all his own way in the third, however, as the former multi-weight world champion rallied to get back into the non-title cruiserweight contest.
But in the fourth, Maccarinelli dropped Jones Jr with a big uppercut, and although he beat the count to resume the fight, the Welshman pinned Jones Jr against the ropes and stunned him with another uppercut before a right hook sent him face first to the canvas and referee Ingo Barrabas waved off the fight.
Victory was the Welshman's third in 2015, and came just two months after he stopped Czech Republic fighter Jiri Svacina in Newport.