Preheat the oven to 220°C (425°F). Line a baking sheet with parchment paper.
Place the grated zucchini in a clean kitchen towel and squeeze out as much moisture as possible.
Transfer the zucchini to a mixing bowl and sprinkle with salt. Let it sit for 10 minutes, then squeeze out any remaining liquid.
In the bowl with the zucchini, add the egg, 1 cup shredded mozzarella cheese, Parmesan cheese, garlic powder, dried oregano, and black pepper. Mix until well combined.
Spread the zucchini mixture evenly onto the prepared baking sheet, forming a 9-inch (23 cm) round crust about 1/4 inch thick.
Bake the crust in the preheated oven for 15 minutes or until it is golden brown and firm.
Remove the crust from the oven and spread the sugar-free tomato sauce evenly over the top.
Sprinkle the remaining 1 cup shredded mozzarella cheese over the sauce.
Return the pizza to the oven and bake for an additional 10 minutes, or until the cheese is melted and bubbly.
Remove the pizza from the oven and sprinkle with chopped fresh basil leaves.
Let the pizza cool for 5 minutes before slicing and serving.