Fastest KO in history?

Grimsley's most notable match was against Jimmy Thunder. In 1.5 seconds Thunder delivered a right hook to the head and Grimsley hit the mat and the match ended. This match serves as the fastest boxing match in history. Before the fight, Grimsley had a 20-1 record with 18 wins by KO and his sole loss being a twelve round decision to George Foreman 4 months prior.