A smart mouth usually beats bullies, but if he's genuinely trying to hurt you, avoid those stupid YouTube videos that have "one crazy tip to win a street fight" or any of that. If you know a thing or two about fighting, an overhand hook is standard for a taller opponent, but you can also aim for the chest if your not confident landing to the face, which can stun a two bit thug who was just expecting you to roll over and take it. One thing to note is that fat guys (like me) tend to have weaker knees, juicy targets for basic kicks. If you don't know how to punch effectively, then pop the guy in the balls enough so he pukes. If he's not trying to hurt you, walk away knowing he's an ass hole and your a better man.