Mandelstam won the
1960 Wimbledon Boys' Singles title by beating
Jaidip Mukerjea in the final. He attended college in the United States at the
University of Miami, where he was a member of the university's tennis team and he earned
All-American honours for three years from 1962 to 64. Mandelstam was inducted into the University of Miami Hall of Fame in 1990. At the
1961 Maccabiah Games in Israel he won a gold medal in mixed doubles with
Marlene Gerson, and a silver medal in men's doubles, playing with Julie Mayers and against American gold medal winners
Dick Savitt and
Mike Franks. Mandelstam competed internationally and won four tournaments between 1962 and 1970. He also participated at the
French Open, the
Wimbledon Championships, and the
US Open. His best result at a
Grand Slam tournament was reaching the third round at the
1962 US Open. ==Junior Grand Slam titles==