In boxing lore, the upset represents the ultimate dramatic device. With one surprising performance, the established order is overturned and a new king announces his arrival on the scene.
All but one of the entries on this list are heavyweight fights. There have been major upsets in every weight class, but in almost any case where I considered a non-heavyweight bout, there were one or more heavyweight tilts from the era that were even more significant.
It should not be surprising that a high percentage of the most shocking upsets have occurred in the heavyweight division. Traditionally the sport's glamor class, for most of boxing history, the heavyweight crown has been viewed as the biggest title in professional sports.
The men who have held the heavyweight belt have been regarded by the sporting public as giants, and it is almost always a shock to see a giant fall.