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 drained zucchini to a large bowl and sprinkle with 1 teaspoon salt. Let it sit for 10 minutes, then squeeze out any remaining liquid.
In the bowl with the zucchini, add 1 large egg, 1 cup shredded mozzarella cheese, 1/4 cup grated Parmesan cheese, 1/2 teaspoon garlic powder, 1/2 teaspoon dried oregano, and 1/4 teaspoon black pepper. Mix well until combined.
Spread the zucchini mixture evenly onto the prepared baking sheet, forming a circular pizza crust about 1/4 inch thick.
Bake the crust in the preheated oven for 15 minutes or until it is golden and firm.
Remove the crust from the oven and spread 1/2 cup sugar-free tomato sauce evenly over the top.
Sprinkle 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 chopped fresh basil leaves on top.
Let the pizza cool for 5 minutes before slicing and serving.