Pokémon S11 E31 A Crasher Course in Power!

"Gotta catch 'em all!"

At the Pastoria Gym Ash challenges Crasher Wake to a 3-on-3 Gym Battle using Pikachu, Turtwig and Buizel, while Wake uses Gyarados, Quagsire, and Floatzel. However, Pikachu accidentally shocks Buizel and this causes them to argue which makes a difficulty in helping Ash defeat Wake. Suddenly, thanks to that Buizel had rescued Pikachu from the attack; their argument concludes. Ash manages to defeat Wake and he earns the Fen Badge.