Who was the last opponent Muhammad Ali knocked out during his professional boxing career?

Richard Dunn (born 19 January 1945 in Halifax) is an English former heavyweight boxer, who fought Muhammad Ali for the world heavyweight title in 1976.

Dunn was defeated by many top boxers of the time, losing to Muhammad Ali, Joe Bugner, Jimmy Young and Kallie Knoetze. However, he did defeat some professional fighters such as Johnny Griffin, Neville Meade, Bunny Johnson and Danny McAlinden.

Dunn is also notable as the only Yorkshireman ever to fight Ali, who knocked him out 2:05 minutes into the fifth round; this was to be the last knockout Ali ever achieved in his professional career. Although he was seriously overmatched, many British fans have said that Dunn made one of the most courageous showings of any British fighter when he faced Ali. Dunn was knocked down five times in five rounds. Dunn lost his next fight to Joe Bugner, surrendering all his titles in a stunning first-round knockout and retired after his next fight, a fifth round defeat to big hitting Kallie Knoetze in the Ellis Park Tennis Stadium in Johannesburg.