(1986) : Often cited as one of her most significant roles, she played a dual character in this adult thriller directed by Jose "Kaka" Balagtas. The film's promotion was substantial enough that its marketing materials, including calendars, were still in circulation a year after its release. Hindi Mapigil ang Init

Born in Atimonan, Quezon, Cojuangco is remembered for her distinct "Oriental features" and her status as one of the most visible actresses of her time, despite not reaching "superstar" status. Her career was relatively short-lived but intense, with over a dozen credits packed into just 24 months.

Beyond these titles, Cojuangco appeared in a variety of other films within the same two-year span: : , Gisingin Natin ang Gabi (as Monica), Alab ng Katarungan , Black Diary , , and Stop: Abortion 1987 Releases : Gawin sa Dilim and Background and Legacy

This is the film that started it all. Cojuangco plays a barrio lass who becomes a mistress to a married contractor. The film is famous for a controversial “buhos” (shower) scene shot in real-time. For years, Silip sa Dilim was lost in bootleg VCD transfers. A remastered copy was uploaded to a private Vimeo channel in late 2024, though no official streaming deal exists.