I do not want this to be a pissing contest. Just relating some things I have seen growing up and heard about, that's all. Just a personal view.
A skilled street fighter will always have the advantage over most martial artist. A skilled street fighter has learned, at a very young age, to fight himself out of a phone booth, back against a wall, doorways, narrow hall ways and other tight areas. Most martial artist need space to operate in. When they learn to fight as well in a phone booth, as an open space, than they are real fighters. And the majority of their fighting/matches are held in a controlled dojo setting. Most street fights only last a max of 5 to 20 seconds. If any one has the bad luck of meeting a good street fighter be aware of the leather sap or a lead filled 4 to 6" pipe he may be hiding. Even a 5 ounce wooden dowel is deadly.
Thai boxer, in my view, have a advantage over the pure martial artist. Kick boxers next in line. One thing about the martial arts, those joint locks, strikes, leg sweeps, submission holds, etc take quite a few years to perfect. And even than they may not be applied correctly in a real street fight. Aikido comes to mind as does Ninja training with regard to years of learning time.. There is an old saying that a good wrestler will always beat a good boxer. For the most part, I believe that.