Mezue ahịrịokwu na-esonụ: Thornton gbalịrị ka a họpụta ya na 1996 NHL draft ma ọ dịghị otu ọ bụla họpụtara ya. Mgbe ahụ, ndị Toronto Maple Leafs wepụtara ya na NHL na
1997, 190th n'ozuzu, Thornton egosighi Toronto ma a gbanwere ya na Chicago Blackhawks n'oge 2001-02 oge. Mgbe oge isii gachara n'etiti NHL na AHL n'etiti franchise Chicago na Anaheim Ducks, Thornton meriri Stanley Cup mbụ ya na oge ikpeazụ ya na Ducks na 2006<unk>07.