Preheat your oven to 350°F (175°C).
Grease and flour an 8 x 4-inch loaf pan.
In a large bowl, whisk together flour, baking powder, baking soda, and salt.
Keep this dry mix aside.
In another bowl, combine sugar and lemon zest.
Add eggs, oil, and lemon juice, then mix until smooth.
Gradually combine the wet ingredients with the dry ingredients.
Gently fold in the shredded zucchini.
Pour the batter into the prepared loaf pan.
Bake for about 55 minutes or until a toothpick comes out clean.