I'm working on a concept for a fighter/rogue character, basically an ex-"cop" (town watchman) who likes to fight dirty - based loosely on Sam Vimes from the Discworld series of novels. I've got this mental picture of him in a fistfight (improved unarmed strike feat) with some larger thug-type, and pulling the old "hey what's that!" and when the opponent turns to look, the character suckerpunches him a good wallop upside the head, using the rogue sneak attack bonus.
So far, the concept is a fighter/rogue with more points in wisdom than anything else. He's streetsmart, insightful, a bit tough, and not too charming due to his gruff no-nonsense demeanor and dark sense of humor. Most of his feats are skill feats, giving him bonuses to listen/spot/search/etc, along with Eyes in the Back of your Head for the no-flanking benefit. I'm looking to find some feat or ability that will allow such a "suckerpunch" tactic in a straight-up brawl. Ideas?
Note that this is for a "random" styled DnD game, with more emphasis on fun times than long-term character planning, so I have no aspirations for any prestige classes, nor do I think we're even going to be using them.