Preheat oven to 350°F.
1. Spray a medium-size baking dish with nonstick cooking spray. Place chicken breasts in the dish. Set aside.
2. In a small bowl, combine the onion, ketchup, water, Worcestershire sauce, vinegar, brown sugar, paprika, chili powder, and onion powder. Mix well and spoon over chicken breasts. Cover with foil and bake 20 minutes. Uncover and bake 10 to 15 minutes or until chicken is cooked through.
3. Serve with hot brown rice.
Makes 4 servings.