Mike Gardner of Kansas City, Mo., defeated Frank Postillion, 21-20, 12-21, 11-10, Sunday to win the 10th annual Bob Symon Memorial Handball tournament at the St. Joseph Y.M.C.A.

Gardner, who had been eliminated in the finals of the tournament in 1981 and 1982, required more than two hours to outlast his opponent, finally emerging in the tie-breaker.

Each player traded leads several times in the tie-breaker, with each getting two serves with the score tied at 10. Gardner won the match and the $800 tournament first prize with an ace of his second serve.

In the tournament's $400 Contender's bracket, defending champion Frank Martin defeated Mike Kelly, 21-8, 2-21, 11-10 to win the $250 top prize. Martin had beaten Roger Gondek, 21-10, 15-21, 11-9, in the semifinals. Kelly bettered Don Stewart, 21-8, 21-20 to gain his finals berth.

Another reigning champion, Phil Robinson, beat Jim Cosentino of Kansas City, 21-20, 20-21, 11-7, to pocket the $250 first prize. It was Robinson's second straight title at the Master's level.