Of the 4 female protagonists, both Misty and Iris beat Ash in a tournament. May tied with Ash in the final AG contest of Sceptile Vs. Blaziken and as far as I remember, Dawn's never beaten Ash in a battle tournament.
Misty beat Ash in the Whirl Cup back in Johto. Her win was decided because Psyduck got a headache and beat Kingler. For some reason the writers played up Ash's stupidity in this battle, and had him forget that if Psyduck's skull was squeezed by a pincer he would get a headache, despite seeing this countless times before. So Misty did beat Ash, but instead of a proper battle, it was another one of Psyduck's dues-ex moments.
Iris beats Ash in the finals of the Don battle tournament, with Excadrill Vs. Pikachu. And since that's finally aired in the dub, let us discuss.
Which win do you think was more justified? Misty beating Ash with Psyduck in the Whirl Cup, or Iris beat Ash with Excadrill?