Based on the vast collective wisdom on this forum, I think I've been able to construct a pretty solid Combat Scenario for this particular situation. It goes like this:
The attacker is in your face, yelling, cussing and poking at you.
You respond verbally by saying "Excellent job - now try it with more emotion..." and then charge him $85 for the "session".
You then immediately follow up with a kiss on the nose and a quick sucker punch to the jaw. Continue by ripping out his windpipe and tearing off his balls (which are then stuffed into attacker's mouth for a choke).
Finish your attacker by running him over with a 72 Buick Electra, then pee your pants and run away squealing like a little girl (i.e. a typical tactical retreat).
It doesn't get any more hardcore than that...

Joking aside - as some people have already pointed out, there are just too many variables here. Depending on the situation, I'd do anything from saying "I'm sorry..." to chopping his head off with a bolo...

Give us a more specific and detailed scenario and I think people will come up with a lot better solutions.
/F