I used to be pretty tough (I know it is almost impossible to believe looking at me now). I grew up on a farm. I got run over by a hay wagon and fell 10 feet into shit and then got trampled by a startled cow. I got run over by a 240 pound pig. I played 4 years of football, and I was actually pretty good. But I got blindsided in practice by a 300 pound guy one day. I wasn't so tough. I went down like I was shot. Then he just laid on me with his enormous heft. I could do nothing except beg to be let up.
Ray Rice outweighs Ms. Rousey by 100 pounds. If he sucker punched her with that short left hook, she also goes down like she was shot. That is just the truth. We don't have "open class" boxing. We don't let 130 pound women fight 230 pound men. There is a reason for that.