Gençsoy spent his entire career at Beşiktaş J.K. between 1938 and 1948 where he achieved numerous local titles, including 3 times Turkish National Division, top-level national football competition between 1937 and 1950. He was the regular right-half of the team at 1938–39 and 1939–40 seasons.[2] In 1940–41 season, along with Hakkı Yeten and Şeref Görkey, Gençsoy contributed the team with 28 goals combined.[3]