how to make sb bow to you?

how to make sb bow to you?I always beat him at the table tennis.But henever show a little bit shame on himself.he often finds some absurd excuse for hisfailure.I beat him again and again justto let him feel ashame.Because he is alwaysbragging his skill(to my eyes,his is verylousy).He is quite old and odd as well.He tries millions of time but still fails,I just want him to bow to me,but henever does that.How can I make him ashameof himself?