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. 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."

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 may 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 may 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.