He played as a winger for MTK Budapest, alongside his two brothers, Vilmos and Adolf,[1] and made one appearance for the Hungary national team.
[3] In 1911, to supplement his income, along with fellow MTK player Izidor Kürschner he set up a photographic studio.
[4] Kertész coached several clubs in Germany, such as Union Altona (1921–1924) and Victoria Hamburg (1924–1928), and in other countries including France and Scandinavia during the 1920s.
[6] In January 1931 he took over at Hamburger SV, where he successfully revamped the team, adding Rudolf Noack and other promising new players[7] until he was appointed by VfB Leipzig in the summer of 1932.
After his contract had been dissolved by mutual agreement in May 1933,[8] Kertész left Germany and emigrated to the United States.