If and only IF the Mayorga being a brutal street thug are true, then Mayorga would murder Pacquiao. No doubt about it. Another thing is that a street fight has no rules, right? What's to stop Mayorga from putting a knife on Pacquiao's throat. Pacquiao ain't a street guy so he will probably "fight clean".

If Mayorga is just bullcrap then Pacquiao would win easily.

Well, Manny didn't grow up in some middle class suburbs either so he's probably just as capable as being brutal. It really depends who gets the punch off first.

The one who fires a gun at the other, its a street fight

Pac would win. He grew up in the streets so he has better survival instincts.