Million Dollar Baby (2005) on Netflix

Wanting to learn from the best, aspiring boxer Maggie Fitzgerald (Hilary Swank) wants Frankie Dunn (Clint Eastwood) to train her. At the outset, he flatly refuses saying he has no interest in training a girl. Frankie leads a lonely existence, alienated from his only daughter and having few friends. Maggie's rough around the edges, but shows a lot of grit in the ring and he eventually relents. Maggie not only proves to be the boxer he always dreamed of having under his wing, but a friend who fills the great void he's had in his life. Maggie's career skyrockets, but an accident in the ring leads her to ask Frankie for one last favor.