Cook beef in a large nonstick skillet over medium-high heat until browned; stir to crumble. Drain well.
Wipe pan with paper towel. Coat with cooking spray; place over medium-high heat. Add zucchini and garlic; sauté 5 minutes. Add beef, seasoning, and sauce; bring to a boil. Reduce heat; simmer 5 minutes. Remove from heat. Add 2/3 cup cheese; stir until cheese melts. Serve over rice. Sprinkle with 1/3 cup cheese.