Larsen won the 1950 U.S. Open Tennis Championships, defeating John Horn, Sven Davidson, Jaroslav Drobný, Tom Brown, Dick Savitt in the semifinal, and Herb Flam in the final.

In 1951, Larsen defended his U.S. Championship, reaching the semifinal where he lost to Sedgman, the champion for that year.

However neither player would represent the U.S. in the Davis Cup Challenge Round, with Tom Brown and Ted Schroeder being chosen instead.

In November 1950, Larsen won the New South Wales Championships at White City in Sydney, defeating the two Australian singles representatives in the Davis Cup Challenge Round, Frank Sedgman and Ken McGregor, in the final two rounds.

It frequently was written that Larsen would arrive for an important match directly from an all-night party with no benefit of sleep.

[7] Larsen's tennis career ended abruptly in November 1956 after a motor scooter accident in Castro Valley, California.

[9] Jack Kramer, tennis player and long-time promoter, stated in his 1979 autobiography that "Larsen was fascinating to watch.

He had concentrated on tennis as mental therapy after serving long stretches in the front lines during (World War II).

He was called Tappy because he went around touching everything for good luck,[10] and sometimes he would chat with an imaginary bird that sat on his shoulder.