If a guy jeers, whistles at, and/or acts like a dick toward your date, isnt it your duty to beat his *** down?

Okay, so I was on my date, walking through the park, when some drunk guy whom we passed starts wolf-whistling at my date and what not. I tried calmly talking it out, and he just got bolder and douch-ier. So I got in his face and shoved him a bit. But he was drunk off his ***, so he fell on it. He takled me, so I shoved him to the ground, then kicked him in the head like a soccer player. His bottle of booze broke, and he grabbed a bit of it and started waving it about and continued his drunken, *** hole-ish rant. At this point I was absolutely pissed, so I produced a knife (just a little three-incher that I always keep on my person) and calmly threatened him with a rather bad *** one-liner of my own invention, and he made tracks. My date was a bit rattled, and she said that I should have just left it, and that I should NOT have pulled the knife. I say otherwise. So, was I in the wrong? Guys, I'd like to know what would YOU have done in said situation? Girls, what would you have thought of what I did if you were in my date's position?