Flash Point (2007)

Sgt. Ma Jun (Donnie Yen) is a Hong Kong police officer with a reputation for violent behavior. He is determined to find and take down three powerful Triad drug dealers (Ray Lui, Collin Chou, Xing Yu). One of his fellow officers, Wilson (Louis Koo), is an experienced undercover agent working within the Triad gang. He and Jun agree to a partnership, but, when Wilson's cover is blown, Jun is forced to confront the gang the only way he knows how: with his fists.