During the early 1940s, following his discharge from the Coast Guard, Lassiter's main running buddy was Rudolph Walter Wanderone, best known as Minnesota Fats. Their town of preference was Norfolk, Virginia, which was known at the time as the highest-rolling place for pool hustlers, card players, and gamblers in general. During these years, Lassiter became the "undisputed king" of the pool hustlers, reportedly winning over $300,000 from gambling on pool games between 1942 and 1948 (including $15,000 in a single week). He often accepted "money games" involving extraordinary sums, often around $1,000 a game. It was during this time that he developed his confidence and skill necessary to begin competing on the professional level with the greatest pocket-billiard masters of the day, including Willie Mosconi and Irving Crane.