After Sonny finds out that his sister's (Talia Shire) husband has beaten her up, he immediately goes to find him, and tracks him down in the street. In the course of opening a 12-pack of whup-ass on his abusive brother in law, he tosses him over a rail. He then picks him up and throws a right hook. Due to the angle of the shot it is very obvious that he misses him by nearly a foot, but the brother-in-law's head still snaps back as if he's been hit.

While some stunts are pulled off better than others, I've never seen a more fake-looking punch in a movie.