His father, Sándor Kleckner, and his uncle, Sándor Hautzinger, were multiple champions in rowing and Olympians of the Pannóna EE. So, it was not surprising that Sándor Korompay (until 1929 Kleckner) also chose rowing. He won the Hungarian championship in 1935 and 1936 with the Pannónia eights. With the same club, he became European champion in 1935, and a year later he finished fifth at the Berlin Olympics. In 1937, he ended his sports career due to his studies, graduating from Pázmány Péter University Faculty of Medicine. Before the Second World War, he worked as a military doctor, then as a radiologist, and retired as a chief physician. In the 1960s, he also appeared in car touring competitions.