In a microwave-safe bowl, combine the tomato sauce, Italian seasoning and garlic powder. Cover and microwave on high for 2 minutes; stir. Cook at 50% power for 3-5 minutes or until mixture simmers, stirring once; set aside.
In a bowl, combine the crumbs, Parmesan cheese and parsley. Dip the chicken into egg, then roll in the crumb mixture. Place in a lightly greased shallow 3-qt. microwave-safe dish. Cover and microwave on high for 10-12 minutes, rotating a half turn after 5 minutes.
Pour tomato mixture over chicken; sprinkle with mozzarella. Cook, uncovered, at 50% power for 3-5 minutes or until meat juices run clear.