You respond only under one of two precepts. Both are SunTzu-inspired, in that they play to your strengths, and not his. There is no glory in these situations. You must WIN, not NEGOTIATE or PARLAY or PLEAD.
1. Turn. Run. Hard. Fast. Kick in a 25~ 200 and almost every would-be assailant has already given up. They are weak pr1cks who want easy prey. Now this is a great moment to turn around, assess the situation - ensuring they are broken - and begin abusing them, "You pVssies!! Thought you could take me, you f### worms! How do you feel now?" etc. Ideally you want to frustrate them sufficiently so they contemplate resuming the chase. Keep a steady gap, eyes on them all the time, and next time they won't even last 100m of hard effort. You're in charge now.
2. You assault the jerk immediately, with terminating force. Do not wait for a scripted escalation - scripted on his part, in which he exchanges insults, threats and then moderate physical acts. Do not give a signal you will go nuclear, just do it, do not do it randomly or with your fists like an untrained boxer. Your action must be hard, direct, immediate, and incapacitating. This means you can't invent it on the spot, you must have trained in this action and repeated it in preparation. So it becomes natural at this moment.
Example: raise heel of hand very hard under chin. This can break an assailant's neck and is incapacitating.
You DO NOT allow the aggressor to follow a script involving shoving you, then punching you before escalating.
Never play by THEIR rules. If you must fight, drop them immediately. Then leave the pr1ck on the floor. Your call if the situation allows you to pi55 on him before you leave.