A Gruff Act to Follow! (Japanese: ズガイドスＶＳピカチュウ！！ Cranidos VS Aipom ) is the 16th episode of Pokémon: Diamond and Pearl.
After Paul dominated the Oreburgh Gym, Ash had to think about what Pokémon he could use. Naturally he chose Turtwig, Aipom and Pikachu to go up against Roark's Rock Pokémon. Will this strategy work, or will history for Ash repeat itself?
Paul thinks Ash wants him to see him lose. Dawn and Pikachu stop the arguing and she tells why not just stay to watch. Paul has no idea who she is, making her angry. Dawn reminds him, but he does not remember, so Brock rushes to calm her down. Ash wants the battle, but Roark wants tomorrow, as he and his Pokémon are exhausted. Ash accepts this and has only to wait.
Team Rocket disguised themselves as scientists and want that fossil. They agree to research for a while and see the huge fossil. A scientist named Kenzo approaches them and asks where he could show the museum. They want to see the machine that restores the fossils, so he takes them to the tower where the machine is. He shows them the machine and the place where the fossilized Pokémon live.
Paul receives his Poké Balls, while Ash decides which Pokémon to use. Brock suggests Turtwig, who is effective against Rock-type Pokémon. With Aipom's Focus Punch, Turtwig's Razor Leaf and Pikachu's Iron Tail, Ash has decided to use them. Staravia is sad, but Ash promises to choose it next time. Brock tells that Roark nearly won because of speed. Ash thinks of this, while Paul tells to copy him. Ash is disgusted, as he remembers well how he treated Chimchar. A boy comes and thanks Paul for Azumarill. Ash now sees Paul gave away the Azumarill because it got defeated. Ash tells him that it can be trained, but Paul tells it was a lost cause and leaves. Dawn thinks what Chimchar and Elekid think of Paul's strategies.
Team Rocket still plan to revive the fossil and see the blueprints of the room where the machine is stored. They remember Kenzo placed a fossil and it takes a day to be revived - an Omanyte was the result. They think they could work at the mines and revive the fossils, though Jessie tells that the workers dig the fossils, while they revive them. Giovanni would be proud that they conquered Sinnoh region.
At the Gym, the battle is about to commence. Roark sends Cranidos, so Brock tells Dawn he wants to see Ash's surprise. Ash sends Aipom, who starts with Focus Punch. Cranidos charges with Headbutt and jumps, giving Aipom some damage. Cranidos uses Flamethrower, though Aipom saves herself using Double Team. Aipom uses Swift, but misses. Aipom uses Focus Punch and Cranidos Zen Headbutt. Aipom is thrown back and defeated.
Ash sends Pikachu. Piakchu starts with Thunderbolt, but misses. Cranidos retaliates with Zen Headbutt, but gets stopped by Iron Tail. Cranidos uses Headbutt and Pikachu jumps, but Cranidos jumps as well and hits Pikachu. Pikachu tries to use Thunderbolt, but gets canceled by Zen Headbutt. Cranidos uses Headbutt and hits Pikachu. Paul leaves, but sees Pikachu is back to his strength and decides to stay. Pikachu uses Quick Attack and Cranidos tries to stop him with Flamethrower, but Pikachu evades and uses Iron Tail on it. Cranidos uses Head Smash and Pikachu Volt Tackle, so they both are taken aback.
Ash calls Pikachu back and sends Turtwig. Turtwig uses Razor Leaf, but gets canceled by Flamethrower. Turtwig dodges and goes to bite, but gets attacked by Zen Headbutt. Cranidos uses Flamethrower, but Turtwig emerges and uses Razor Leaf, finally defeating Cranidos. Still, it was one Pokémon, so Roark has two left. Roark sends Onix. Turtwig uses Razor Leaf, but Onix dodges and counters with Double Edge. Ash has no choice but to send Pikachu. Pikachu uses Iron Tail and is countered by Slam. This causes damage to both Pokémon. Pikachu uses Thunderbolt on the field. Onix uses Double Edge, but gets stopped by the rocks of the battle field. Pikachu charges with Quick Attack, but gets stopped by Screech. Pikachu is thrown against a stone and while he looks okay, he falls down defeated.
Ash goes to get Pikachu. Paul leaves, calling that pathetic.
- This is the second time Ash lost his first Gym Battle since IL005: Showdown in Pewter City.
- Interestingly, Ash battled Brock and Roark, who specialize in Rock-type Pokémon.