Charles Bronson hops off a train, gets a cup of coffee, and then walks into a warehouse where a toughman fight is going on. James Coburn's man is losing. Next scene Bronson gets Coburn to sponsor him, and the next ninety minutes involve Coburn getting himself into trouble and Bronson beating the shit out of people to get him out.
Simple, elegant, bullshit-free plot. Sure, there's an aside with a woman, but it amounts to little. The love interest side-plot is there just to highlight how this ain't that kinda movie.
What really matters is the atmosphere. Crummy apartments, factory floors, dockyards. All peeling paint and wet concrete. Places populated by ugly men with acne scars and bad teeth.
Good hard-boiled dialogue without getting too cutesy.
Prime Walter Hill. Highly recommended.