In June 1956, she met Armando Bo on a TV show, who later offered her the opportunity to star in El trueno entre las hojas (Thunder in the Leaves). Bo convinced Sarli to be naked in a scene in which she bathed in a lake, though she had previously been told she would wear a flesh-colored body stocking. Also, though Bo likewise told Sarli they would shoot from afar, the camera had magnification. The film became the first to feature full frontal nudity in Argentine cinema. She went on to become an international Latin American star and made international headlines for the nude scene. She appeared in Time, Life, and Playboy Magazines, the first Argentinian Actress to accomplish that feat. Bo and Sarli became lovers and she became the primary star of his films till his death in 1981. During this time, Sarli refused many offers to work with another Director, with the exception of Leopoldo Torre Nilsson on Setenta veces siete (The Female: Seventy Times Seven) and Dirk DeVilliers on The Virgin Goddess, her only English film.