Green’s Dictionary of Slang

1. the penis.

1788		Harris’s List of Covent-Garden Ladies 76: [She will] engage your champion of her ring with a grasp, till he is reduced to bend beneath the powerful squeeze and yield all the metal he has about him.
1904		Lustful Memoirs of a Young and Passionated Girl 35: Evidently the presence of his champion in her pussy gave her great pleasure. [Ibid.] 39: He got on top of her then placed the head of his champion between the lips of her monkey.

2. (US black) an attractive, sexy woman.

2006

G. Pelecanos Night Gardener 269: Shame if we had to kill her. Ain’t too many champions walkin around like that.