Mighty Mo made his K-1 debut on February 15, 2004 at "K-1 Burning" event in Japan against Hiraku Hori. He knocked out Hori at 1:22 in 4th round by right hook. After losing in semifinals at his first 8-man tournament in Las Vegas against fellow American Dewey Cooper, Mighty Mo made a huge comeback four months later at the "Battle of Bellagio II", winning his first K-1 GP Championship by knocking out Brecht Wallis in 2nd Round at the tournament finals.