O'er the Rampardos We Watched! (Japanese: クロガネジムふたたび！決戦ラムパルド！！ Return to Kurogane Gym! Decisive Match with Rampald!!) is the 18th episode of the Diamond & Pearl
Ash returns to Oreburgh Gym, ready to challenge Roark again. As the battle starts, Ash quickly surprises everyone when Pikachu manages to take down Onix. As the second battle begins, Ash pits Aipom against Geodude. After a long struggle, Ash manages to beat Geodude, and loses Pikachu and Aipom before the real test begins, defeating Roark's newly evolved Rampardos.
Ash returns to the Gym for the rematch. Roark marks he gained confidence and has a chance to win. Dawn is dressed as a cheerleader, as they both trained, and will cheer for him, along with Piplup and Buneary. Roark sends Onix and Ash his Pikachu. Pikachu starts with Quick Attack and Onix with Slam. Pikachu used the move to go onto Onix. Onix uses Screech and Pikachu moves to its head. Onix waves its head to get it off and Pikachu uses Iron Tail to hit it hard. Onix uses Double Edge. Piakchu charges as well, but Pikachu spins, using Dawn's combination from before.
Pikachu attacks with Iron Tail, but misses. Onix uses Slam and bashes him on a rock. Onix uses Stealth Rock, but is stopped by Thunderbolt. Onix uses Screech, but this does not stop from being defeated by Pikachu's Iron Tail. Roark is amazed by Ash's skills, but does not back down, as Geodude is sent out. Ash returns Pikachu and sends Aipom.
Meanwhile, Team Rocket is sneaking and Meowth unlocks a door with his claws. They go inside the Gym to take whatever they find inside. Croagunk senses something and goes away, without Brock noticing it going. Aipom starts with Swift and Geodude rolls, but hits an illusion created by Double Team. Aipom uses Focus Punch, but gets blocked by Geodude. Geodude gets her and performs a Seismic Toss, bashing her on the ground, then begins to roll again. Aipom dodges by spinning herself and quickly defeats Geodude by a Focus Punch.
While Roark has only one Pokémon left, it is still powerful, while Aipom and Pikachu are exhausted. Roark is impressed, but has one last ace - he sends Rampardos. Ash decides to use Aipom. Aipom uses Swift and hits Rampardos, but it did not evade, yet still seems unhurt. Rampardos retaliates with Headbutt and hits Aipom before she could even react. Aipom is defeated, while Brock believes Roark is putting Ash to the test - his Rampardos defeated Aipom in one move. Ash sends Pikachu to the battle.
Team Rocket wanders to the battle field and spot Croagunk. Meowth tries to convince they are not here to steal anything, though Croagunk makes steps to them. Pikachu uses Thunderbolt, though Rampardos evades and attacks it with Zen Headbutt. Pikachu goes to spin, but fails and gets injured. Pikachu charges with Quick Attack and Rampardos tries to stop him with Headbutt, but misses. Rampardos uses its tail to throw him up. Pikachu goes down using Iron Tail and the attack is countered by Zen Headbutt. Pikachu's Static ability activates, but does not work, as Rampardos' Mold Breaker prevents it from being paralyzed. Pikachu is defeated by Zen Headbutt.
Croagunk got Team Rocket out. Jessie thinks it wants to become one of them, but gets hit by Poison Jab. James and Meowth grab her and run away. Ash sends Turtwig and it charges. Rampardos uses Headbutt, though Turtwig jumps and spins across it. Rampardos goes to use its tail, but Turtwig bites it, then tosses it against a boulder. Turtwig uses Razor Leaf, but gets negated by Flamethrower. Rampardos charges with Head Smash. Turtwig uses Razor Leaf to stop it, but does not work and gets attacked.
Turtwig heals itself with Synthesis and quickly evades the Flamethrower. Ash has an idea to beat Rampardos - Turtwig charges, while also using Razor Leaf. Rampardos stops the attacks with Flamethrower. Roark realizes that is not what Ash desired and Rampardos uses Headbutt. However, Ash declares Turtwig to jump and Rampardos jumps, but Turtwig slides under Rampardos. Turtwig uses Razor Leaf and hits Rampardos, who gets defeated. Ash wins the battle. Later, Roark gives Ash the Coal Badge, his first Sinnoh badge.
- Ash receives Coal Badge.