Battling the King of the Mines! (Japanese: 地底のジム戦！VSヤーコン！！Underground Gym Battle! VS Yakon!!) is the 61st episode of the Best Wishes series, and the 718th episode of the Pokémon anime. It first aired in Japan on January 5, 2012 and in the United States on May 12, 2012.
After fulfilling Clay’s request for the rare Revival Herbs, Ash is more than ready for his Gym Battle...and finally, so is Clay! They proceed to the battlefield in the Driftveil Gym, located deep underground in one of Clay’s mines. The battle will use three Pokémon per side. Clay starts by bringing out his powerful Krokorok, and Ash realizes that he can’t use Pikachu, who’s been eager to battle, because its Electric-type moves won’t work at all against Clay’s team of Ground types. He picks Oshawott instead, and the battle begins!
Krokorok is powerful indeed, but Ash executes a brilliant strategy to knock it out and give him the lead. Then Clay brings out his Palpitoad, which appears to be much stronger than Ash’s own Palpitoad. Oshawott is defeated with a crushing Rock Smash, and Snivy is up next. Another unusual strategy and an excellent type advantage lead to Palpitoad’s defeat, and Clay is not pleased.
Finally, the Gym Leader turns to his secret weapon—a super-strong Excadrill, whose Rapid Spin keeps deflecting Snivy’s attacks until it’s able to knock Snivy out. Both sides are down to just one Pokémon left, and Ash calls on Roggenrola, hoping its toughness will keep it standing against repeated powerful attacks from Excadrill.
Excadrill’s attacks are unyielding, but sure enough, Roggenrola endures—and then evolves into a powerful Boldore, which turns the tide of the battle considerably! Both Boldore and Excadrill are extremely tough, and the attacks continue to fly—but in the end, Boldore emerges victorious, and Ash wins the Quake Badge! Then, upon Nurse Joy’s recommendation, our heroes set their sights on the Mistralton City Gym, where Ash will vie for his sixth Unova Gym badge!
Returning to the Driftveil Gym with the Revival Herbs from Milos Island, Ash for the third time, comes to the Gym to finally battle Clay. As the door to the Gym opens a Worker answers and lets Ash, Cilan, and Iris inside when Ash presents the bag of herbs to the worker. The worker leads them to an elevator and they descend down deep underground to a mining tunnel. Ash sees Clay and presents the bag of Revival Herbs to him. Seeing as they are good quality he accepts Ash's request for a Gym battle. Clay leads the group to a wall and press a button on the door that leads them to the Gym Field.
Iris and Cilan head to the sidelines as Ash enters the field. The Referee declares that the Gym battle will be a three-on-three match and then begins the match. Clay sends out his first Pokémon, a Krokorok. Pikachu eagerly wants to battle Krokorok but Ash quickly reminds Pikachu that Electric-type moves don't work on Ground-types, so he'll have to sit out this match. Ash sends out his Oshawott then promptly commands an Aqua Jet, but Krokorok dodges Oshawott by using Dig, causing Oshawott to crash into the wall. Krokorok leaps out the ground then unleashes Sandstorm, causing sand to fly furiously on the field. As Oshawott is buffeted by the Sandstorm, sand gets into his eyes, blinding him. Krokorok uses Bite on Oshawott. Oshawott tries to attack with Razor Shell, but with sand in his eyes, Oshawott just blindly swings his scalchop around wildly. Krokorok attacks with a Stone Edge. Oshawott takes a considerable amount of damage. Oshawott barely stands up from Krokorok's attacks as well as Sandstorm's effects. Clay tells Krokorok to finish the round up, however an idea pops into Ash's mind. He orders Oshawott to use Water Gun on the field. Oshawott rapidly spins as he fires off a Water Gun to create a water geyser which causes a downpour, effectively stopping the sandstorm as well as washing out his eyes. Krokorok digs underground but Oshawott fires a Water Gun into its hole, flushing it out into the air. Oshawott proceeds to use Aqua Jet which scores a hit on Krokorok, then finishes it off with a Razor Shell.
Iris comments that Oshawott's super effective moves helped Ash win the round. Cilan reminds Iris that Krokorok is only his first Pokémon. As Clay returns Krokorok back into its Poké Ball, he praises Ash for his gutsiness, but reminds him to stay serious as he sends out his next Pokémon, a Palpitoad. Iris notes that Clay's Palpitoad seems a lot stronger than Ash's Palpitoad. Ash asks Oshawott if he's okay, and Oshawott nods his head. Oshawott fires a Water Gun, but Palpitoad counters with a Hydro Pump. Both attacks collide, but Hydro Pump has much more power, thus it dissipates Oshawott's Water Gun and sends him into the wall. Oshawott shakes off his damage and proceeds to use Razor Shell, however Palpitoad fires a Sludge Bomb which hits Oshawott and knocks his scalchop out of his hands before he could unleash his attack. Oshawott retrieves his scalchop, but Palpitoad slams Oshawott into the ground using Rock Smash, knocking him out. Ash returns him to his Poké Ball.
Clay taunts Ash saying that his gutsiness has come to an end. Ash assures him that he isn't finished yet. Realizing that Palpitoad is both a Ground and Water-type Pokémon, Ash sends out his Snivy. However instead of starting off with a Grass-type attack, Ash orders Snivy to use Attract, which causes Palpitoad to become infatuated. Snivy attacks with Vine Whip followed by Leaf Blade, both hitting Palpitoad without any problems. Clay tries to get Palpitoad to snap out of his infatuation, but with no avail. Snivy finishes off Palpitoad with a Leaf Storm, knocking him out.
Clay is furious by Ash's tactic by using Attract, stating that it isn't a strategy or fair. Ash is left utterly confused. Clay takes off his hat and scrunches it in his fist then throws it to the ground. Clay sends out his best Pokémon, an Excadrill! Excadrill lets out a roar. Snivy starts off by using Vine Whip, but Excadrill counters with a Rapid Spin, deflecting all of the hits. Snivy tries to attack with a Leaf Blade, but Excadrill easily overpowers Snivy with another Rapid Spin. Snivy then tries to use Attract, but once again, Excadrill stops the attack with Rapid Spin. Snivy desperately tries to attack with her last move, Leaf Storm, but, again, Rapid Spin overpowers her move. Excadrill unleashes a devastating Horn Drill attack, instantly knocking out Snivy.
Iris and Cilan are amazed by Excadrill's sheer power. As Ash returns Snivy to her Poké Ball, Ash declares that he isn't ready to throw in the towel and declares his dream to become a Pokémon Master, so giving up in the Gym isn't an option. Clay tells Ash that he's still naïve and shows Ash his prized pickaxe. When he was Ash's age, he and Excadrill worked hard mining to become where they are today. Clay blames that Ash is just lightly throwing around his dream to the world without truly working hard. Ash defends that he is serious to become a Pokémon Master, and he'll show it with his last Pokémon. Clay says that it's all talk for now. Ash assesses his situation, he needs a Pokémon that can endure Excadrill's power. Ash decides to send out his Roggenrola. Iris and Cilan are confused why Ash chose a Rock-type Pokémon to face a Ground/Steel-type Pokémon. Cilan thinks Ash chose it for its grit. Roggenrola starts off with a Sandstorm, but Excadrill digs underground using Drill Run and then attacks Roggenrola from under its feet then quickly digs back into the ground and repeatedly attacks with Drill Run. Roggenrola is tossed across the field, taking each successive hit. After being pummeled by multiple Drill Runs, Roggenrola is winded, but still standing. Clay is amazed that it hasn't fainted yet, but then decides to wrap it up with a Horn Drill attack. Excadrill slams his drill into Roggenrola, however Roggenrola does not fall. In fact, it doesn't make a sound at all. Ash is worried, he calls out to it, but then Roggenrola begins to glow!
Roggenrola evolves into a Boldore! Ash quickly scans it with his Pokédex, finding out that Boldore has learned some new moves. Excadrill's attacks with Horn Drill, but Boldore endures the hit with Sturdy. Excadrill attacks with Drill Run, but Boldore catches Excadrill before it could hit it. Boldore and Excadrill both try to wrestle the other to the ground, but both are equally matched. Suddenly Boldore's crystals begging to glow. Understanding the power building in Boldore, Ash orders Boldore to attack with Rock Blast. Excadrill takes the attack and stands up, but drops down to one knee. Boldore's crystals continue to glow, and Boldore attacks with its newly learned Rock Smash as Excadrill does the same. As both Rock Smash attacks collide, a huge shockwave shakes the ground. However, Excadrill winces from its damage and Boldore takes the opportunity to overpower Excadrill and slams it into the ground. As the dust settles, Excadrill is on the floor, knocked out. Boldore is declared the winner and Ash wins the match.
Ash runs out to the field and hugs his new Boldore. Boldore happily jumps onto Ash, knocking him onto the ground. Ash continues to praise Boldore as Clay smiles at Ash. Outside of the Gym, Clay thanks Ash for the great battle and encourages him to continue his journey to become a Pokémon Master. Clay presents him with the Quake Badge, thus Ash now has five Unova Badges. Later that night at the Pokémon Center Ash, Iris, and Cilan chat about the Gym Battle. As Nurse Joy returns Ash's Pokémon, she asks him what he plans on doing next. Ash declares that he'll go and get his sixth Badge at the next Gym available. Nurse Joy recommends that he should continue on to Mistralton City, thus Ash, Iris, and Cilan plan on heading there next.