The Fourth Round Rumble (くさのフィールド！いがいなきょうてき！ Grass Field! An Unexpected Powerful Enemy!) is the 77th episode of Pokémon: Indigo League.
As Gary lost his recent match, Ash battles an opponent named Jeanette. While Bulbasaur managed to defeat her Beedrill and Scyther, Ash's luck goes down as Jeanette sends Bellsprout, who evades attacks and can repel Pokémon's moves. However, Ash has a secret ace he has not used in quite some time, which turns the side of the battle back to him.
Gary faces Melissa, using Nidoking against her Golem. Nidoking uses Horn Attack, but Golem stops him and uses Seismic Toss. Nidoking is defeated and Melissa wins, striking Gary hard for this defeat. The heroes saw the event. Later, Ash approaches Gary, who goes to his car. Gary tells him he was distracted by his cheerleaders. He tells the girls they will get over it, then goes in the car and goes away. Ash tells Pikachu if Gary lost, wouldn't they quit. Brock tells him he will not quit, as he and Pikachu believe in him. Misty tells that his match is soon to be on the grass field, making Ash surprised.
Jessie and James sell the souvenir, while Meowth reminds them they are here to steal some Pokémon. James is happy for this normal job and waters his Victreebel and gets latched by it. A customer appears, wanting to buy some badges, but Jessie and James reply they have none left. Meowth tells they have and going in the back, Jessie and James see that he is making the badges out of bottle caps. Ash goes to the stadium, while Misty and Brock watch him battle. Misty hoped they would have given him advice, but Brock tells Ash wanted to win by himself. Misty thinks a Bulbasaur would be a good Pokémon to battle and asks Brock who is Ash's opponent. Brock says that he only knows the woman's name is Jeanette Fisher.
A red carpet emerges from the hall and Jeanette appears, with a lot of cheerleaders. Misty sees she has a lot of cheerleaders while she and Brock cheer for Ash. Brock seems dazed by Jeanette, so Misty yells to have him remember they are on Ash's side. Ash sends the Pokémon Misty mentioned, Bulbasaur, while Jeanette her Beedrill. Beedrill goes to tackle, but Bulbasaur dodges. Bulbasaur uses Razor Leaf, but Beedrill dodges and retaliates using Twineedle. Bulbasaur dodges, including the Poison Sting. Misty hopes Jeanette does not have Pokémon like Beedrill and Brock hopes she does not have a boyfriend, making Misty yell at him once more. Beedrill gets entangled by Leech Seed, making Brock Jeanette is losing. Bulbasaur tackles Beedrill and wins.
Jeanette calls Beedrill back and sends Scyther. Scyther goes to slash, but misses, so uses Quick Attack, hitting Bulbasaur. Bulbasaur uses Vine Whip, but Scyther's attacks repel the move. Scyther uses Double Team, making Bulbasaur to be in a difficult position. Bulbasaur uses Vine Whip and banishes the illusions, though the real Scyther charges and attacks Bulbasaur. Bulbasaur uses Razor Leaf, but misses. Scyther uses Double Team and attacks Bulbasaur, as it misses with Vine Whip and gets hurt. Bulbasaur uses Vine Whip to banish the illusions and attack the real Scyther, defeating it. Misty and Brock are impressed, as Ash won two battles without their help. Team Rocket are having the balloon as decoy while they go to get the people's Pokémon. Two Officer Jennys see this and Growlithe uses Flamethrower to burn the balloon down. James goes to start the hose, but the Officer Jennys made the machine turn off and chase them. While escaping from the police, Team Rocket trip over and bump into a stand, but quickly stand up as salesmen selling hot dogs and ice cream.
Jeanette sends her last Pokémon, a Bellsprout, making Ash, Pikachu, Misty and Brock surprised. Ash believes Jeanette does not have any strong Pokémon and sent Bellsprout. Ash believes this battle is going to be the shortest one in the Pokémon League history, as Bulbasaur goes to tackle. Surprisingly, Bellsprout lifts Bulbasaur and sends it behind. Bulbasaur attempts to attack once more, but gets thrown away. Bellsprout comes to Bulbasaur and trashes it, then bangs it to a wall and wins. Ash calls Bulbasaur back (quite shocked at how Bellsprout won) and sends Pikachu. Pikachu uses Thundershock and misses. Bellsprout uses Razor Leaf and, though Pikachu dodges, the leaves cut some nearby rocks in half. Pikachu uses Thunderbolt and hits Bellsprout, but it does not seem hurt, as Jeanette says that the legs were binded to the round and did not conduct electricity - hence no damage. Pikachu goes to punch and kick Bellsprout, but misses and gets hit when Bellsprout kicks it with its roots.
Misty and Brock are baffled how can Ash win this, as Bellsprout is Jeanette's strongest Pokémon. Suddenly, Oak and Delia appear to watch the match, sitting next to Misty and Brock. Oak knows his grandson lost, but looks on the bright side, saying that "it'll do Gary good to learn that every road, no matter how smooth, has its bumps along the way". Ash's mom and the professor yell that since Gary lost, everyone in Pallet Town cheers for him. Ash sends a Pokémon he hadn't seen in a lot of time, his Muk. Jeanette is disgusted, while Oak says that Ash wanted Muk and asked to get it yesterday. Oak admits he underestimated this choice. Bellsprout uses Jump Kick, but lands inside Muk. Bellsprout kicks, punches and throws Muk away, but Muk does not take damage. Bellsprout uses Razor Leaf, but Muk is not dealt damage. Muk retaliates with Body Slam, engulfing Bellsprout. Bellsprout attempts to free itself, but gets defeated. Ash runs to Muk, who hugs him, making Ash say that he now knows how Bellsprout felt. Jeanette lifts Bellsprout and goes away.
Jessie and James admit it was much more fun and profitable selling than stealing stuff. Meowth thinks they would open a fast-food restaurant. Jessie and James admit it is not a bad idea and think about a motto. Misty tells Ash he won, but without Muk he wouldn't have no luck. Muk hugs Misty for this sentence, and everyone laughs.
- This is the first time James's Victreebell latches onto his face.
- The "Who's that Pokémon?" in this episode is Bellsprout.
- Officer Jenny calls her Growlithe "Arcanine" as she orders it to flamethrower Team Rocket's balloon.
- When Oak said that he underestimated Ash's choice for Muk, his eyebrow was miscolored.
- Jeanette's Scyther used Double Team and Swift, moves it cannot learn.