Betty v. the homeless guy

This post is a shout-out to all those nerdy boys who ask who would win if paired off in a cage match - Bruce Lee or Muhammad Ali? Ah, a question for the ages.
I thought summer was the season where all the mentally ill homeless people come out of hiding. Maybe there's something about the cold that triggers a mental break...
Two nights in a row I have seen a homeless guy (not the same one) yell at random people on the street and try and fight them. The first was really scary. There was some young college kid who was just standing at the corner waiting to cross the street. He had his little back-pack on and clearly just came from class. He seriously looked MAYBE 18. This guy comes up to him and starts yelling at him - totally nonsensically. The 18 year old didn't know what to do, and did what most people do - tried to ignore him. The light changed and the 18 year old started to cross. Luckily (I guess) he must've been more freaked out than he looked (which is saying something) and he noticed when the homeless guy started running after him yelling something that indicated he wanted to beat the kid to a pulp.
I don't know where it came from, but I went from being a little bit freaked out to Protecto - Girl and started to turn around to follow them to - what? fight the guy for the 18 year old? I think that's where my instincts were going - nuts as that is. Luckily, I didn't have to test where I was going, because I saw that the kid got away, and I turned back to continue on my path home. Anyway, I couldn't help asking myself who did I think would win? Maybe I could give him one of those notorious double punches that are impossible to guard against.