Ash is to battle Ritchie in the next round of the Pokémon League competition. Misty is looking up some information on the computer about him. She finds that Ritchie won all of his first four rounds with just one Pokémon. Ash goes to the Pokémon Center and finds Ritchie there who was just picking up his Pokémon. Ash promises Ritchie a great battle the following day. Ash picks up his Pokémon and returns to the small house where he is staying to sleep for the night. The next day, they receive a phone call. It is Ritchie’s voice, and rudely insults Misty over the phone. She hands it to Ash, and the voice tells Ash to meet him outside at a specific location and to bring Pikachu. When Ash arrives, he finds Ritchie (it is a dummy, except Ash thinks it is really Ritchie) and suddenly is trapped by Team Rocket. They throw him in their van and drive away, keeping Ash from the competition. Ash escapes using Squirtle to flood the van, and Team Rocket are up to their eyeballs in water. The back bursts open, and Ash starts to run back to be in time for the competition. Team Rocket get in his way again, bent on keeping him away from the league competition. He uses Bulbasaur and Pikachu to whip and shock them. He continues towards the league, but Team Rocket catch up on bicycles. They use Weezing to smog him out, but he hops on a bicycle and continues along. They catch up to him in their balloon and hook the bicycle. They start to float away, and so Pikachu is carried up by Pidgeotto to give them another big shock. Team Rocket is then blasted off into the forest. Pidgeotto then starts to carry Ash toward the stadium. Meanwhile, back at the stadium after already being given ten additional minutes after the battle was supposed to start, they are about to declare that Ash has forfeit the match. Just as they almost declare Ritchie the winner, Ash shows up floating toward the stadium in the Team Rocket balloon. They begin the battle, and Ash sends Squirtle against Ritchie’s Butterfree named Happy. Squirtle loses, and so Pikachu leaps out to battle and defeats Happy. Ritchie calls his Charmander and it defeats Pikachu. Ash is out of reliable Pokémon, as Bulbasaur would lose for sure, and so he desperately sends out Charizard. Charizard actually battles, and defeats Charmander. Ritchie lastly sends out his Pikachu named Sparky. Charizard blows Sparky around a bit, deeming it to not be a worthy opponent and lays down for a nap and reckless. Since Charizard apologizes to Ash and temporary ignored to battle Sparky won, and Ash was defeated by Ritchie. Despite his immense disappointment, Ash looks up and congratulates Ritchie, and they are still friends in the end.
Despite having the Earth Badge, which (in the games) makes ALL Pokémon obey, Charizard still wouldn't obey Ash.
The "Who's that Pokémon?" in this episode is Aerodactyl.
One theory on why Ash lost is that all his pokemon were tired out by Team Rocket. If this was the case then Ash fought an unfair battle an lost, but he did come very close to winning. So if Team Rocket hadn't tired out ash's pokemon then maybe ash might have won. Ash even says that pikachu was tired during the battle, this helps back up the theory.
At the end of the battle it was Charizard verses Sparky, Ash lost because Charizard temporary ignore to battle, but if it had, then most likely Ash would have won.