Preheat the oven to 350°F and adjust the rack to the center position.
In a large mixing bowl, combine the ground beef, rice, egg, onion, garlic, Italian seasoning, salt, and pepper. Use your hands to thoroughly incorporate the ingredients. Shape the mixture into approximately 20 meatballs, each about 1.5 inches in diameter. Place the formed meatballs in a 9×13-inch baking dish.
In a separate medium bowl, mix the tomato sauce, chicken broth, Worcestershire sauce, garlic powder, and brown sugar. Stir until well blended, then pour the sauce evenly over the meatballs in the dish.
Cover the baking dish tightly with foil to ensure the rice cooks properly. Bake for 1 hour. If the rice remains undercooked, return the dish to the oven until the rice has softened.