In self-defence.
I agree with you. I count myself as fortunate that I have never been in a situation that got to such a point, but in my opinion confrontation is confrontation and battery is battery. Gender is completely irrelevant. If someone attacks you (man or woman) you have the right to defend yourself using whatever means are necessary. If a man can walk away I agree that's best but I would say that whether the other person is a man or a women. Sometimes though it's just not possible and I don't believe a man should have to "stand there and take it" to avoid public ridicule.
If you (in general, not you specifically) can't control a woman short of striking her then it's time to turn in your Man Card and go find another gender.