at Forest Hills N.Y., in 1951, Kramer withdrew with back trouble after a five-set win over Parker. Kramer was not ranked in the USPLTA professional ranking due to insufficient U.S. tournament play (having withdrawn from the Forest Hills U.S. Pro and having been absent from the Cleveland U.S. Pro). Kramer was ranked U.S. No. 4 professional for 1951 behind Kovacs, Segura, and Gonzales by the PTPA. Some recent tennis writers have considered Kramer to be World number one for the 1951 period. Kramer was described as "world champion" or "world's professional champion" throughout 1951. 1952 At the Philadelphia Masters Indoor, Kramer lost both of his matches to Gonzales, who won the tournament. At the Roland Garros Round Robin Professional event in Paris, Kramer defeated Gonzales but lost to Segura, who won the tournament. At the 1952 Wembley Professional Championships, Kramer lost a close five-set final to Gonzales, regarded as one of the classic all-time matches. Kramer was not ranked in the 1952 U.S. professional rankings by the USPLTA or the PTPA, both of which ranked Segura professional No. 1 followed by Gonzales at No. 2. Kramer did not play at the U. S. Pro (billed title Cleveland International Pro), which was won by Segura. Some recent tennis writers have considered Kramer to be World No. 1 for the 1952 period. 1953 Kramer beat Frank Sedgman, 54–41, in the 1953 World Series and was referred to as "world champion" again. Kramer did not play in any of the larger tournaments in 1953. Kramer was ranked No. 3 professional for 1953 by the Players' Committee of the Cleveland World Pro in June behind Gonzales and Segura. Kramer was given a World No. 1 professional tennis player reference by The Sacramento Bee newspaper for 1953. He was ranked World No. 1 pro by Frank Sedgman in October 1953. Kramer was ranked behind the World No. 1 ranked Sedgman in the 1953 Tennis de France full season rankings, which included the results from Europe, published by Philippe Chatrier. Some recent tennis writers have considered Kramer to be World No. 1 for the 1953 period. Kramer retired from competitive tennis in 1954 due to arthritic back problems and went on to promote his Pro Tour. 1954 & 1956 Kramer played matches during an Asia tour in September and October 1954 with Pancho Gonzales, Frank Sedgman and Pancho Segura. In 1956, Kramer played a few undercard