Two-time Olympic gold medalist and former PFL champion  Kayla Harrison made her octagon debut at UFC 300 and dominated former bantamweight champion  Holly Holm .  Harrison considers herself the ‘uncrowned queen’ of the bantamweight division.   On Saturday, she took on second-ranked  Ketlen Vieira in a fight that will likely produce the next title challenger.  Vieira entered the match coming off a win over Pannie Kianzad in July.  She has wins over two former champions,  Miesha Tate and Holm, and planned to end the Harrison hype train. Vieira landed first with a leg kick.