order operator not working with 'UNION' expression

CREATE DATABASE `test9`CHARACTER SET utf8 COLLATE utf8_general_ci; 

USE `test9`; 

CREATE TABLE `test`( `ordering` INT UNSIGNED ); 

INSERT INTO test(ordering) VALUES (5),(2),(4),(3),(9),(8); 

SELECT 0

UNION ALL

(SELECT ordering FROM test ORDER BY ordering)

ordering  

----------

         0

         2

         3

         4

         5

         8

         9

     0  

--------

       0

       5

       2

       4

       3

       9

       8