Kickboxing vs boxing in a street fight?

The kickboxer would most likely win. The moment the boxer hits the kickboxer in the face, the boxer's hand will most likely break. The face is one of the hardest areas on the human body, that's why they give boxer's gloves. If you hit there with a boxing punch and no protection, you will likely break your hand. The harder and more properly you hit, the more damage you will receive as well ,meaning boxers are even more likely for this. Since the kickboxer will have shoes on, his feet won't be a problem and he will be hitting even harder than normal.