Place chops in a 9x13 inch baking dish and top each one with an onion slice and a lemon slice. Add 1 tablespoon brown sugar and 1 tablespoon ketchup on top of each pork chop.
Cover dish with aluminum foil and bake in the preheated oven for 30 minutes. Remove cover and bake another 30 minutes or until internal temperature of meat has reached 160 degrees F (70 degrees C). While baking, baste occasionally with pan juices.