Sopal, who has previously faced elimination several times, broke down in tears after her poignant performance with professional partner Julian Caillon.
Judges Anton Du Beke and Shirley Ballas offered high praise, with Ballas stating Sopal would "always be a hero" and her performance gave her "chills".
Motsi Mabuse comforted Sopal, acknowledging the emotion conveyed through the dance, while Craig Revel Horwood noted some technical flaws but praised the performance's flow and feeling.
The performance was part of the show's musicals special, which also featured other routines and will include a performance by the Strictly professionals.