Lakmini made her official entry into mainstream Sinhalese cinema as a newcomer in Nalaka Vithanage’s romantic drama Sarungal . Playing the character of Asanki alongside co-stars Charith Abeysinghe and Saranga Disasekara, she portrayed a young woman caught in a web of modern relationships and emotional conflicts.
In her very first movie, Chamathka delivers a quiet yet deeply affecting performance that anchors the film's emotional core. The most memorable moment in Sarungal occurs early in the film, where Asanki is shown spending a lonely night in a nightclub. As she sits alone, weighed down by her troubled marriage to Bhanuka, she catches the eye of Amila—a man equally trapped in a loveless relationship. The scene of their first encounter is tender and intimate; without many words, Asanki's tears move Amila deeply, and in return, she understands his pain as if it were her own.