Mumbai, Sep 07 (ANI): Bollywood diva Priyanka Chopra had her fingers crossed over commercial success of her latest film, which is a biopic based on the life of Indian boxer, Mary Kom. "Mary Kom" released in cinemas across India on Friday (September 05). The movie was premiered in Toronto. Priyanka has had roles in some big budget franchises such as "Krrish" and "Don" and has also won plaudits for playing role like an autistic woman in the film "Barfi". But it is her portrayal of Olympic medalist and five-time World Amateur Boxing champion Mary Kom, which has proved to be the biggest task as an actor so far. Chopra said playing the role of a living, breathing person of nearly her own age has been the greatest challenge of her acting career so far and she learnt the lesson of never give up during the course of shooting of Mary Kom.