Between 1905-24, László Beleznai was a swimmer and a water polo player with MAFC. In 1912, he was the Hungarian 100-yard freestyle champion with a time of 58.6 seconds. In 1911 and 1912, he was a member of the 4x100m freestyle relay national championship-winning team. In 1910 and 1912, Beleznai was the Austrian 100- and 200-metre freestyle champion, and in the latter year broke the 100m national record in 1:05.4. From 1912-24, he played seven times with the national water polo team. He was a member of the Hungarian Swimming Federation (MUSZ) from 1918 and the following year became a member of the first water polo referee examining committee. Following the death of Béla Komjádi, Beleznai served as coach of the national water polo team (1934-36). In this period, the Hungary won the 1936 Berlin Olympic gold medal. In 1929-30, Beleznai was the executive vice-president of MUSZ, and from 1929-47, was a member of the Board of the International Swimming Federation Association (FINA). In 1947-48 he was appointed co-president of MUSZ.
Personal Best: 1:05.4 (100m freestyle)