Bring large pot of water to boil, add spaghetti and cook per package directions.
While pasta is cooking, heat olive oil in a large, deep nonstick skillet on medium-high heat. Add garlic and chili flakes and cook for 1 minute, stirring continually. Add zucchini noodles, salt and pepper and cook, tossing gently, for 1 to 2 minutes or until zucchini has softened. Stir tomatoes, spinach, lemon zest and juice gently into zucchini mixture until well combined. Cook for another 1 to 2 minutes or until spinach is wilted and tomatoes are warmed through.
When pasta is done, drain and add to skillet mixture. Remove from heat.
Heat 2 to 3 inches of water in a large saucepan to boiling. Adjust heat to keep liquid simmering gently.
Break eggs, 1 at a time, into a cup. Holding dish close to surface, slip egg into water.
Cook eggs until whites are completely set and yolks begin to thicken but are not hard, 3 to 5 minutes. Do not stir. Lift eggs from water with slotted spoon. Drain in spoon or on paper towels. Trim any rough edges if desired.
Divide zucchini and pasta mixture among four dinner plates or bowls, top each with 1 poached egg and garnish with basil. Serve immediately.
