Serial kisser Emraan Hashmi said that his forthcoming flick "Once Upon A Time In Mumbai", in which he dons the role of an underworld don, is a "turning point" in his film career.

The actor also said that he has worked really hard on his looks for 'Once Upon…'

Emraan added that working along with multi-talented actor Ajay Devgan is a great experience.

Hashmi said, "Working with Ajay was a treat because he is such a great actor. To be in one frame and act with him is intimidating, but you get to learn lots of things."

The actor, who has played roles with negative shades in his earlier flicks, stated that "Once Upon A Time..." would be a turning point for him and maintains that it's unlike other dark underworld films.

Directed by Milan Luthria, the film has been set mainly in the 1970s Mumbai.

The movie will trace the changing face of the underworld through the eyes of a police officer. The story follows the rise of Sultan (Ajay), and his eventual fall when his protege Shoaib (Emraan) challenges his supremacy and usurps power to rule the underworld in the city.

'Once Upon…' also has Kangana Ranaut and Prachi Desai.

Emraan has really worked on his body for this film, but says he detests the term "six-pack abs". (With Inputs from Agencies)