|This article relies largely or entirely upon a single source. (August 2011)|
Fontana was the year-ending number two ranked Canadian player six times, three times in the 1950s and three more in the 1960s. He was ranked in the Canadian top-ten five more times. He won the Canadian Open doubles championship three times, in 1955, 1957, and 1959 with compatriot Robert Bedard, and was a runner-up four more times.
Don won the Ontario Open singles tennis championship twice, in 1956 and 1957. He was a Pan American Games competitor twice, in 1959 and 1963.
Fontana represented Canada in Davis Cup eight times from 1955 to 1963 and had a career win-lose record of 7 and 15, 4 and 8 in singles and 3 and 7 in doubles. He was Canadian Davis Cup captain five times between 1963 and 1976.
Fontana was tournament director of the Canadian Open in 1959 and from 1971 to 1978. He was also a long-time tennis TV analyst for CTV's coverage of the Canadian Open.
Don was inducted into the Tennis Canada Hall of Fame in 2000.
Fontana is also one of the last people to have ever played tennis with the legendary Bill Tilden. According to Frank Deford’s authoritative biography of Tilden, Big Bill Tilden, at pp. 273-74, in 1953 Fontana and Bedard, while on tennis scholarships at UCLA, were invited by Tilden to play tennis with him and Tilden’s protegé Art Anderson on Charlie Chaplin’s tennis court in Los Angeles in a mock-Davis Cup format of the U.S. versus Canada (the Canadians won both the first two singles and the doubles for an insurmountable 3-0 lead). Tilden, age 60 then, was found dead in his apartment a few days later on the eve of his proposed departure for the U.S. Pro Championships in Cleveland, Ohio.