Regaining the Home Advantage! (Japanese: 爆走！ジバコイルＶＳメタグロス！！Loud Roar! Jibacoil VS Metagross!!) is the 158th episode of the Diamond & Pearl series, and the 624th episode of the Pokémon anime. It first aired in Japan on January 7, 2010 and in the United States on June 5, 2010.
As the journey to Daybreak Town and Dawn’s next Pokémon Contest continues, our heroes are passing through the forest when they are suddenly attacked by a wild Magnezone! They later speak to Officer Jenny, who informs them that the wild Magnezone, as well as a wild Metagross, are attacking a nearby town, and no one seems to know why. Fearing for the town’s survival, Pikachu and Pachirisu start shooting Electric attacks into the sky in an attempt to lure the two wild Pokémon back up to the mountain.
Later on, Ash and friends run into a patrolman named Crispin, who tells the group that the two wild Pokémon always battle in a basin in the mountain. They battle there in order to release the magnetic charges that the mountain produces from time to time, but the basin has mysteriously been flooded. As they figure out how to remedy the situation, Team Rocket decides to get the two wild Pokémon to join them...with the help of some negotiating by Meowth. But their plan fails over and over, and they are sent blasting off again.
With the help of Buizel and Happiny, the water in the basin is frozen and then lifted up and into a deep crevasse. The basin is ready for Magnezone and Metagross to battle happily once again!
As Ash and his friends continue their journey to Sunyshore City, they are attacked by a wild Magnezone. As they reach a nearby town, they are informed by Officer Jenny that Magnezone — soon joined by a wild Metagross — has suddenly appeared and is wreaking havoc throughout the town. Ash, Dawn, and Brock direct their Pokémon to stop the fighting, but the Magnezone and Metagross prove too powerful.
Meanwhile, Team Rocket, after failing to give a Gible to the boss, is having a literal toast to themselves when the very same Magnezone and Metagross suddenly and unintentionally attack them, blasting them off.
Meanwhile, Brock suggests that they lead the two Pokémon down the mountain with electricity to keep them from destroying the city. Pikachu and Pachirisu are up for the job, but before they reach their destination, Jessie, James and Meowth interrupt. They want to pay back the two battling Pokémon for disturbing them not once, but twice. Brock asks Meowth to talk to the two Pokémon to ask them why they are fighting, but even he can't understand the strange metal language. Team Rocket blasts off after a hit from Metagross. With no other options, Pikachu and Pachirisu use Thunderbolt and Discharge respectively and repeatedly in order to continue leading Magnezone and Metagross down the mountain.
The group meets up with Crispin, a mountain guard. Crispin informs them that the two Pokémon normally battle with each other on a regular basis to release the magnetism that builds up in their bodies, due to the strong magnetic forces emitted from the mountains. Recently, however, their "battle arena" (a deep crater) has become filled with water. Ash, his friends, Officer Jenny, and Crispin realize they have to find out why the crater is full of water, and then find a way to drain it, so Magnezone and Metagross can battle in peace, away from the city.
They discover a boulder diverting a stream to the crater, and Team Rocket reappears to move the obstacle with their balloon. Unfortunately, the boulder is too heavy and their balloon ends up falling in the river. Brock then sends out his Croagunk, which uses Brick Break to break the rock, restoring the normal flow, taking Team Rocket with it. With the water no longer flowing to fill the basin, they can now drain it. Team Rocket returns and tries to help once again by using their pump to drain the crater.
Unfortunately, their pump's motor is weak, meaning that it would take too long to get the water out. Therefore, Brock suggests freezing the water. Dawn sends out her Buneary to use Ice Beam on the crater. Unfortunately, since Team Rocket's pump hose was still in the water, they get frozen too. Brock then sends out Happiny to lift the ice out of the basin (with Team Rocket as well). Despite Team Rocket's begging, Happiny throws the ice and them into the valley. With their battle area freed of water, Magnezone and Metagross can battle as much as they want, out of the way of the city.
Deep into battle, however, Team Rocket appears again and tries to appease both Pokémon by claiming they saved them both, not Ash nor his friends. This backfires, and an explosion launches Team Rocket into the sky, away from the crater. The battle continues, but then Ash sends his Gible, who fails Draco Meteor once again, knocking Piplup from the ledge and making him fall into the crater. The episode ends with Piplup crazily dodging Magnezone's and Metagross's attacks.