Lineal championship

In combat sports where champions are determined by challenge, the lineal championship in a weight class represents an intangible world title first held by the victor of a bout between top contenders in the division.^[1] A fighter who defeats the reigning champion in a match within the same weight class becomes the next lineal champion. In professional boxing, the lineal champion is informally known as "the man who beat the man."^[2][3]

There is no universally recognized protocol for establishing the start of each championship lineage, leading to the absence of a single canonical list of lineal champions. A lineage can be disrupted when the reigning champion retires or changes weight class. Other factors such as prolonged inactivity, legal issues, or the inability of a champion to defend their title can also contribute to such disruptions. Additionally, when a sanctioning body such as the WBA, WBC, IBF, or WBO strips a title, this action is generally disregarded in determining the lineal champion.