Well in a street fight anything goes. But most of the time people just start swinging wild punches. Beautiful thing about Muay Thai is that stand up is "your house". A trained figher will see wild punches as if they were in slow-motion. Even if the person would try to grab you there are clinch moves you can use to destroy them. If you develop exellent footwork, great hands and legs, knocking out a stupid aggressor in mere seconds is not unheard of. Having great cardio endurance to run away from dangerous situations will also be a breeze