Lilienthal, of Jewish origin, was born in Moscow, Russian Empire, and moved to Hungary at the age of two. He played for Hungary in three Chess Olympiads: Folkestone 1933 (scoring +7−0=6 as the reserve, the fifth player on the team), Warsaw 1935 (scoring +11−0=8 on second board), and Stockholm 1937 (scoring +9−2=6 on , leading his team to the silver medal). He won the individual gold medal for his board (reserve and second board, respectively) at the 1933 and 1935 Olympiads, and had the fourth-best result on first board in 1937. His total score in the Olympiads was 75.51%.