In 1966, with only 22 months of training, Lewis won the grand championship of the 1st tournament he entered, The U.S. Nationals promoted by Jhoon Rhee. Lewis defeated 7 opponents before defeating Thomas Carroll by 2–0 decision. Lewis reigned as the U.S. Nationals grand champion from 1966–1969. At the 1967 Nationals in Washington, Lewis won the championship by defeating Mitchell Bobrow in the semi-final and beating Frank Hargrove 3–2 in the finals. Previously, Lewis defeated Hargrove in New York City at 'Henry Cho's Karate Tournament'. During that time he defeated Chuck Norris.