Gotta go with Bernard Hopkins final fight against Joe Smith Jr. where Bernard was blasted through the ropes and out of the ring landing on the concrete floor. Who ya got?
I'm going with the pitiful shell of Muhammad Ali losing to Larry Holmes. (I was just reminded that this was not Ali's last fight. Just ignore me.)
While that fight was indeed painful to watch, Ali's last fight was actually a loss 14 months later against Trevor Berbick
Ali's sad, fumbling loss to Trevor Berbick in 1981, where I actually thought he looked pretty good for a guy as ill as he clearly was, gloves reused, and they had no actual ringside bell, so a cowbell was used. The entire event was shambolic, and not a fitting end to such a career
I remember Anthony Crolla boxing a Spaniard in his farewell fight in March 2020 where he clearly lost but was given the decision.