In 1957, he joined the Dallas, Texas-based promotion Big Time Wrestling under the ring name "Crusher Duggan", winning the NWA Texas Heavyweight Championship later that year.

[2] On July 19, 1961, Simon unsuccessfully challenged Buddy Rogers for the NWA World Heavyweight Championship in Jacksonville, Florida.

He adopted the persona of "Otto Von Krupp", a German wrestler who wore jackboots and a swastika on his back.

[5] In 1962, playing upon Cold War tensions, Simon adopted the persona of "Boris Malenko", an agent of the Soviet Union.

His main rivals included Eddie Graham, Wahoo McDaniel, Johnny Valentine, Joe Scarpa, and José Lothario.

On May 9, 1972, Malenko and Bob Roop defeated Bearcat Wright and Bobby Shane to win the NWA Florida Tag Team Championship, and six days later, Malenko defeated Wright in singles competition to win his eighth and final Florida Brass Knuckles title in Orlando.

On June 24, 1972, Malenko and Johnny Weaver defeated Mike Webster and The Professional for his second run with the Florida Tag Team titles.