In a lot of media, you'll have scene where a battle going on. The battle stops when The Rogue sneaks up behind an enemy and holds a dagger to their neck, forcing all of the victim's allies to surrender.
My instinct is that this is a readied coup de grace following a grapple, but there's no way I know about that lets you make an opponent helpless short of tying them up, which isn't what's going on in the scene above. Any ideas?