Superman has 3 weaknesses: Kryptonite, a red sun, and magic. Goku's main weakness is his stamina. In the main DC universe, Superman doesn't even use his full power because there are only a handful of beings in the DC universe who can survive that type of power. Yes, Goku can teleport, but he still has to get close to Superman to attack him. Why? Because shooting a kamehame wave just doesn't cut it when your opponent can fly at a very high speed. Shooting energy blasts also make Goku vulnerable to attacks from behind. It will have to be a good ole slugfest. And when that happens, Goku simply doesn't have the stamina to go toe to toe with the Man of Steel.
The clear winner here is Superman because not only will both fighters fight with their full power but they will also fight clean.