Preheat oven to 350°F. Grease a 9 x 5-inch (or 8 ½ x 4 ½ -inch) loaf pan.
In a large bowl combine flour, baking powder, baking soda, salt, both sugars, oil, vanilla, and eggs. Stir until a thick batter forms.
Fold in the grated zucchini until just combined, the batter will loosen and become pourable.
Scrape into the prepared pan and smooth the top.
Bake 65 to 75 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs. Tent with foil during the last 10 to 15 minutes if the top browns too quickly.
Cool in the pan for 10 minutes, then transfer to a wire rack.