Pace - The Final Frontier! (Japanese: 決戦！VSレジアイス！！Deciding Match! VS Regice!!) is the 190th episode of the Advanced Generation series, and the 464th episode of the Pokémon anime. It was first broadcast in Japan on August 31, 2006 and in the United States on February 17, 2007.
With Charizard out of the battle for his rematch against Pyramid King Brandon, Ash calls out Bulbasaur. Dusclops performs Mean Look again, while Bulbasaur wraps the Ghost-type with Leech Seed. The two Pokémon are evenly matched, but Bulbasaur takes a beating from the Fire-type move Will-O-Wisp and is affected by Confuse Ray, which causes it to use Vine Whip on itself. Because Leech Seed is taking energy from Dusclops and giving it to Bulbasaur, the Grass-type manages to stay in the fight, using SolarBeam to knock Dusclops out.
Brandon sends out Ninjask next, while Ash sends out Squirtle. The two move quickly, and are perfectly matched until Ninjask blinds Squirtle with Sand-Attack. Squirtle listens for its opponent, and eventually recovers by clearing out its eyes with Hydro Pump. Squirtle strikes with Skull Bash, knocking out Ninjask. Brandon then calls out Solrock. Squirtle stays in the battle, but eventually Solrock takes it down with SolarBeam, a Grass-type move.
Meanwhile, Team Rocket is sneaking into the Battle Pyramid, but they are caught and blasted away by Regirock and Registeel. In battle, Ash sends Bulbasaur back out, who does a good job of dodging. Eventually Solrock and Bulbasaur face off with their SolarBeam attacks, resulting in a double KO. Ash and Brandon send out their final Pokémon, Pikachu and Brandon's new Regice. Regice's attacks quickly ice up the field, making it hard for Pikachu to keep steady. Pikachu still makes an impact with Thunderbolt and Iron Tail, but Regice traps Pikachu and then uses Rest to heal up. Regice hits Pikachu with Ice Beam, freezing it in a block of ice, and the Electric-type is almost defeated, but Pikachu breaks out with Thunderbolt and strikes back with Iron Tail. Regice attempts to trap Pikachu and use Rest again, but Pikachu breaks down and charges with Volt Tackle, knocking out Regice.
Ash is awarded the Brave Symbol, making him a Master of the Battle Frontier and entering him into the Hall of Fame. Scott offers Ash a Frontier Brain position, but he turns it down in favor of more traveling. Squirtle, Charizard, and Bulbasaur all return to their homes.
Bulbasaur takes another Will-O-Wisp, and tries to use Vine Whip, but the vines are out of its control and begin whipping Bulbasaur itself. Another Will-O-Wisp sends Bulbasaur flying, and Ash catches it. The vines attacks itself and Ash. Ash yells out to Bulbasaur, and Bulbasaur snaps out of its confusion. With Bulbasaur no longer confused, Ash orders Bulbasaur to try Solar Beam again. While Bulbasaur is charging the attack, Dusclops tries to defeat it by firing Will-O-Wisp, but this time Bulbasaur dodges and fires Solar Beam, knocking out Dusclops.
Brandon summons Ninjask, and Ash swaps for Squirtle. Ninjask uses Aerial Ace, but Squirtle's Rapid Spin repels the attack. Ninjask uses Sandstorm to send Squirtle flying before using Double Team to surround it. Squirtle fires Water Gun at all of them, revealing Ninjask. Ninjask dodges Water Gun and strikes with Aerial Ace. Ninjask uses Sandstorm, but Squirtle's Hydro Pump neutralises it. Ninjask then uses Sand-Attack to blind Squirtle. Ninjask uses another Aerial Ace, but Squirtle can't see in order to evade. Ash tells Squirtle to listen for it. Squirtle dodges and uses Hydro Pump, but the attack goes high. Ninjask executes another Aerial Ace, but the Hydro Pump attack comes down and clears Squirtle's eyes, allowing it to counter with Skull Bash and knock out Ninjask.
Brandon sends out Solrock. Squirtle uses Hydro Pump, but Solrock's Psywave pushes it back. Confusion stops Skull Bash and sends Squirtle back. Solrock fires Shadow Ball but Squirtle uses Hydro Pump against the wall to dodge. Squirtle attempts a Rapid Spin, but Solrock dodges. Squirtle crashes into the wall and takes Solrock's Solar Beam, an attack which takes out Squirtle.
Ash sends Bulbasaur back out. Solrock uses Psywave, but Bulbasaur dodges and fires Razor Leaf. Solrock uses Confusion to stop the attack, and sends the leaves back at Bulbasaur. Bulbasaur charges with Vine Whip, but Solrock uses Confusion again to sends Bulbasaur flying, but it bounces off the wall. Solrock fires Shadow Ball, but Bulbasaur dodges. It fires Leech Seed, hitting Solrock and begins sapping away its energy. Solrock fires another Psywave, hitting Bulbasaur. Bulbasaur fires Solar Beam, which Solrock matches with its own. Both attacks collide, and the force causes a double knockout.
Underneath, Team Rocket digs into the chamber where Regirock and Registeel are kept. They use Lock-On to target Team Rocket, before firing dual Hyper Beam attacks that send Team Rocket flying.
Ash sends Pikachu out, and Brandon calls upon Regice. Scott realizes that this must be the Pokémon that Brandon had discovered earlier. Pikachu fires Thunderbolt, which Regice endures easily. Regice uses Blizzard, which Pikachu takes. Pikachu attacks with Iron Tail, with Regice countering with Ice Beam. Pikachu dodges, but the attack freezes one half of the field and negates the attack. Pikachu uses Quick Attack, but Regice negates it with another Ice Beam, which freezes the other half of the field. With the field covered in ice, Regice can move quicker, but Pikachu ends up slipping. Regice attempts to use Focus Punch, but Pikachu uses Thunderbolt to paralyze Regice, and then strikes the Iceberg Pokémon with Iron Tail. Regice uses Ice Beam to freeze the stadium more, creating a tomb of ice pillars that trap Pikachu.
With Pikachu immobilized, Regice uses Rest. Pikachu uses Iron Tail to free himself. Pikachu races towards Regice, but it wakes up and fires Ice Beam, this time making a direct hit and freezing Pikachu in an ice pillar. Ash orders Thunderbolt, but Pikachu seems unable to. The referee begins to declare Pikachu unable to battle, but Pikachu uses Thunderbolt to shatter the ice and paralyze Regice again. Regice fires another Focus Punch to send Pikachu bouncing across the ice field. Ash manages to get Pikachu to use two Iron Tails in a row due to the ice. Regice uses Ice Beam to trap Pikachu in another icy tomb before using Rest again. Pikachu frees himself with Iron Tail and starts charging forward with Volt Tackle. Regice wakes up and uses Ice Beam to try to freeze him again, but Pikachu dodges and hits Regice before it can launch another attack, knocking it out. Ash wins the match.
During Ash's flashback with Bulbasaur, Bulbasaur is seen flipping Vincent's Meganium inside a building while Ash is wearing his Advanced Generation series clothes, battling a Zangoose, and battling an Arbok with May and Max in the background. Bulbasaur's only battle against Vincent's Meganium took place outside, when Ash was still wearing his original clothes, while the other two battles never took place.
When Solrock uses Confusion on Bulbasaur, Bulbasaur was seen using Vine Whip, even though Ash had never commanded Bulbasaur to do so.