The heroes are having lunch. Piplup accidentally pushes Pikachu's food away, so they go to search it. When they find it, a Pichu eats it. The heroes go find them and see Pikachu is fighting a Raichu. The man who owns Raichu and Pichu notices Piakchu is not a wild Pokémon and wants to trade. Ash is not interested, so the man tells him he is not interested in anything, though he would like to complete his "set". To prove him wrong, Ash challenges him to a battle.
Ash introduces himself, while the man is Sho. Sho wants them to attack first, so Pikachu uses Thunderbolt, but does not seem to have affected Raichu, while Raichu uses Thunder. Pikachu and Raichu collide with Volt Tackle and follow with Iron Tail. Pikachu uses Quick Attack, but does not seem to affect Raichu. Raichu uses Hyper Beam, so Pikachu tries to dodge, but Raichu binds him to a rock and hits him. Pikachu is badly hurt by this move and Sho leaves, telling Ash he is pathetic. Paul comes as well and also confirms Ash is pathetic, but proposes Pikachu should evolve. Dawn recalls Pikachu needs a Thunderstone to evolve. Suddenly, Pikachu collapses, so the heroes go to the Pokémon Center.
Nurse Joy immediately treats him. Team Rocket is also touched by the event and thinks Pikachu should not evolve. Pikachu remembers his memories of himself and Ash. Thinking of the last battle, Pikachu falls in coma. Nurse Joy electrocutes Pikachu and after several times, Pikachu is stabilized. Later, Pikachu wakes up and goes away, but Ash gets him, though he wants a re-match. Ash remembers the Thunderstone Nurse Joy from Vermilion City gave to him for Gym Battle against Lt. Surge. He places the stone near Pikachu, in case he wants to evolve. During the night, Pikachu wakes up and sees the stone and thinks a while. The heroes enter the room and see Pikachu and the stone are gone, so go to search.
Ash sees some lightning and finds Pikachu safe. Team Rocket also appears with the Thunderstone, but leaves. Ash promises Pikachu to train it tomorrow. Next day, the heroes go and see Paul, who leaves without a word. Ash trains with Pikachu by spinning and see lightning, so they go towards it. They find Sho training his Raichu and Ash challenges him to a battle. Sho accepts, but thinks that it will not change the outcome. Ash wants Sho to attack first, so Raichu uses Iron Tail, but Pikachu evades and runs in circles. Still, one attack hits Pikachu and pushes him in air. Raichu charges with Volt Tackle, but Pikachu stops it using Iron Tail. Raichu uses Volt Tackle, but Pikachu spins to dodge.
Team Rocket watch the battle and cheer for Pikachu, although secretly. Raichu uses Iron Tail, but Pikachu evades running in circles and gets hit by Quick Attack. Raichu uses Iron Tail, but Pikachu spins and uses Iron Tail. Next, Pikachu charges with Volt Tackle and uses Iron Tail to deal massive damage to Raichu. Raichu uses Hyper Beam and binds Pikachu to the tree, though Pikachu uses Thunderbolt for protection. Sho is surprised, but Ash tells him size does not matter this time. Raichu uses Iron Tail and Pikachu does the same, but Pikachu links the tail and throws Raichu to a tree. Raichu uses Hyper Beam, but fails to bind Pikachu to the tree. Pikachu spins and uses Iron Tail, defeating Raichu.
The heroes and Team Rocket are happy to see Pikachu won, while Paul goes away. Team Rocket plan to sell the Thunderstone. Sho congratulates on Ash's victory, but promises the next time they clash, the result will not be the same.
- Electric Shock Showdown premiered over a decade before this episode. The Thunderstone is not mentioned at any point between the two episodes.
- 113, Chansey's National Pokédex number, was often shown in the machine used by Nurse Joy in the Pokémon Center. In addition, 74, the number of this episode in the Diamond & Pearl series, is also shown. It could also be a reference to the animation production joke A113.
- To My Best Friend and Pokémon Symphonic Medley were both used as background music.
- The dub title is a reference to David and Goliath.
- Ash makes an appearance in each of his previous outfits through still paintings of his memories.
- Pikachu's spinning aerial Iron Tail is visually identical to Pikachu's neutral-aerial attack in the Smash Bros. series. Red's Pika also imitated this technique in the Pokémon Adventures manga.
- Team Rocket doesn't blast off or recite their motto in this episode.
- Team Rocket says they don't want Pikachu to evolve, but they tried to evolve it 53 episodes earlier.
- Professor Oak's Pokémon lecture: Paul's Electabuzz
- In the Hindi dub, when Pikachu quickly tries to rush off to get Raichu during his recovery in the Pokémon Center, Ash asks Pikachu if he really does want to evolve into Raichu. However, in the original as well as in the English dub version, Ash just says that it needs to rest.