If she simply scratched or slapped me, I might not retaliate it with physical violence, at least in term of a clenched fist. An aggressive shove or a simple slap in return might be enough, but you never know when natural reflex will take over and you'll end up punching a bitch before you can even think.
Something that really grinds my gears is some women thinking they can have all of the same rights as men but also think they're entitled to a few privileges on top of it, like striking a man without fear of being struck back just because they're a woman. Well, in the famous words of Steve Austin, EH EH!
I don't advocate violence of any sort (for the most part) but I see zero wrong with hitting a woman if she throws the first slap/punch/etc. She's an adult, if she can dish it out, she can take it, too.