Ash's exhibition match with Professor Kukui continues, with Tapu Koko having unexpectedly entered the match in the place of Kukui's final Pokémon and its Electric Surge having covered the battlefield with an Electric Terrain. Naganadel uses Sludge Bomb, but Tapu Koko uses Steel Wing to shield itself from the attack and proceeds to use the same move offensively when Naganadel uses X-Scissor. Naganadel readies another X-Scissor, but it is hit by Tapu Koko's Dazzling Gleam. When Ash orders Dragon Pulse, everyone is shocked by this since Tapu Koko is a Fairy-type Pokémon and thus immune to Dragon-type moves. However, instead of hitting Tapu Koko, the attack goes past it and hits the ground below, stirring a lot of dust, which skews Tapu Koko's visibility. Naganadel lands an X-Scissor on its opponent. Tapu Koko charges through a barrage of Sludge Bombs to batter Naganadel with Dazzling Gleam and Discharge, which outruns Naganadel's Thunderbolt and defeats the Ultra Beast. Ash takes a moment to thank Naganadel for its assistance before recalling it back to its Beast Ball.
Ash calls Pikachu out as his final Pokémon, and it uses Thunderbolt first. The attack collides with Tapu Koko's Dazzling Gleam. Pikachu then uses Quick Attack, but it fails to strike the airborne Tapu Koko. Kukui orders Tapu Koko to retaliate with Dazzling Gleam, but Pikachu leaps out of the way and counters with Iron Tail. Tapu Koko prepares to use Nature's Madness, but Ash calls for an Electroweb, which contains the attack. Tapu Koko is again stunned by the stirred dust, allowing Pikachu to land a clean hit and send it towards the battlefield. Pikachu follows up with Electroweb, pinning Tapu Koko to the ground. Tapu Koko attempts to break its restraints using Discharge, but Pikachu stops it with Thunderbolt, creating a blinding yellow explosion of electricity.
After the explosion has cleared up, the Electric Terrain dissipates and Kukui congratulates Ash on how much he's grown during the League. Tapu Koko approaches Kukui, pointing at his Z-Ring. Kukui realizes that Tapu Koko wants to launch a Z-Move, but he explains that it isn’t possible as he already used up his Z-Move with Incineroar earlier. Determined, Tapu Koko breaks out into sing and summons its fellow guardian deities to Manalo Stadium. The united quartet begin harmonizing together, showering the stadium in glittering scales. Both Ash and Kukui's Z-Rings start glowing, signaling that their Z-Power has been recharged. Tapu Koko also offers Kukui a Tapunium Z crystal, previously thought to have been only an ancient myth. Kukui is taken aback, but complies with Tapu Koko's wishes. He calls out to Ash and orders him to launch his Z-Move at the same time, which Ash happily agrees to. Kukui performs the Z-Pose pose perfectly, passing on the ancient power to Tapu Koko. The ground trembles and the field fractures as a yellow headless giant emerges from underground, shocking everyone watching.
Everyone in the stadium is startled by the sheer gargantuan Ash has to now face. Ash's attention, however, quickly turns to his Z-Power Ring as it begins sparking, his Electrium Z suddenly transforming into a Pikashunium Z. Ash promptly puts his hat on Pikachu's head and prepares his own full power Z-Move. Tapu Koko takes its position as the head of the titan as Kukui orders it to attack with Guardian of Alola. Pikachu unleashes 10,000,000 Volt Thunderbolt, and the two signature Z-Moves clash. Ash and Pikachu briefly find themselves in a white void, where Ash tells Pikachu how they had felt the power of Alola throughout their travels across the region, and now it was time to become one with that power. With extreme effort, Pikachu's ultimate Z-Move finally overpowers Guardian of Alola, enveloping Tapu Koko in a bright burst of energy. The blinding collision clears, with Ash and Pikachu visibly exhausted by the combined effort. Tapu Koko begins to descend gently, before collapsing onto the debris-littered field. Hala makes the official judgment, ruling Tapu Koko unable to battle and proclaiming Ash as the winner of the exhibition match. Ash finally collapses from both exhaustion and relief, while the crowd erupts into cheers and applause, and Ash's classmates are overjoyed.
While Ash fully realizes he just won, Tapu Lele showers the battlefield in its sparkling scales, helping both Pikachu and Tapu Koko to recover from the exhausting battle. Kukui leaps forward and thanks Tapu Koko for its help with a handshake. Pikachu and Ash also thank their formidable opponents for the spectacular match. With the Manalo Conference now officially completed, Professor Kukui takes a moment to gaze over the crowd and he declares the League a success. Ash agrees, earning himself a pat on the head from his mentor. Kukui warns Ash not to get too overconfident from his victory, and the young Trainer accepts the advice.