I saw a movie many years ago (25+) and haven’t found it again since. US made movie.

It starts with a woman walking through a parking lot and she’s being harassed by some guy and a stranger steps in and rescues her. The stranger protects her throughout the movie from whoever is after her and it doesn’t end well for him. I think at some point they go to one of his friends who is a bit of a military but with a bunker and loads of weapons. The final scene is a repeat of the first, she is being harassed by same dude and a new stranger comes to the rescue.