In 1935, Vass took part in the Singapore Open and reached the mixed doubles final with Alice Pennefather, where they finished as runners-up after losing to Seah Eng Hee and Aileen Wong. He did not compete in the men's singles or doubles events after conceding walkovers in both. In September, Vass competed in the inter-club championship against Novices Badminton Party and suffered his first local defeat in a competitive singles match, albeit in a team setting, when he lost to the newly crowned Singapore Open men's singles champion, Leow Kim Fatt. Diehard ultimately lost to Novices Badminton Party 2–3.
