Girlfight (2000)

Trouble comes too easily to Diana Guzman, a high school senior with a chip on her shoulder and nameless, aimless scores to settle. Running an errand one day for her father Sandro, Diana finds herself in one of Brooklyn's most famous boxing gyms. At the sight of boxers sparring in the ring, her mind explodes with the promise that you can be someone through the swiftness of your fists and your will to do harm -- finally, a place where she might belong! She starts secretly training to be a boxer, and wakes up quickly to find aches, pains, and an emotional tug-of-war with Hector, her world weary trainer. The discipline, cunning, and sheer hard work required to be a contender are the cold shower Diana needs to stir an ambition she's neglected all her life. Things get messy when she falls in love with another young boxer -- a guy whose ambivalent tenderness toward her puts her on the defensive, and whose fluid boxing style sharpens her own competitive edge.