Pace - The Final Frontier!\決戦！ＶＳレジアイス！ (Japanese: Deciding Match! VS Regice!!) is the 45th episode of Pokémon: Battle Frontier.
Ash continues his battle against Brandon. With faith in his Bulbasaur, Ash finally manages to beat Dusclops. Then, Squirtle faces off against the speedy Ninjask and manages to pull off a narrow win. Squirtle isn't so lucky when he faces down Solrock. Solrock defeats Squirtle and the Bulbasaur and Solrock knock each other out. Then, it comes down to the final battle: Pikachu vs. Regice. Will Ash win and become the Battle Frontier champion?
Ash recalls Charizard and sends Bulbasaur. Team Rocket climbs the walls of the Battle Pyramid to sneak on everyone. Dusclops uses Shadow Punch, hitting Bulbasaur. Bulbasaur retaliates with Razor Leaf, hitting Dusclops. Dusclops uses Mean Look, so Bulbasaur uses Vine Whip, though Dusclops uses Shadow Punch, hurting Bulbasaur. Bulbasaur uses Leech Seed, launching a seed on Dusclops to steal its energy. Dusclops uses Will O' Wisp, so Bulbasaur counters it with Razor Leaf. Next, Bulbasaur uses SolarBeam. However, Dusclops uses Confuse Ray, affecting Bulbasaur, who launches the SolarBeam on Team Rocket (who were on the roof) and is blasted off.
Dusclops uses Will O' Wisp, hitting Bulbasaur. Bulbasaur uses Vine Whip, but is hitting itself. Dusclops launches another Will O' Wisp, hurting Bulbasaur. Ash catches Bulbasaur before it hits itself in the wall, but Bulbasaur uses Vine Whip on itself and Ash. Ash tells Bulbasaur he always fought for helping others and with those words, Bulbasaur is not confused anymore. Bulbasaur uses SolarBeam, so Dusclops goes to attack with Will O' Wisp, but Bulbasaur evades and launches the attack, defeating Dusclops. Brandon calls it back and sends Ninjask. Ash calls Bulbasaur back and sends Squrtile. Ninjask uses Aerial Ace, but is not effective against Squirtle's Rapid Spin. Ninjask uses Sandstorm, engulfing Squirtle, then uses Double Team. Squirtle uses Water Gun to banish the illusions and goes to hit the real Ninjask. However, Ninjask uses Aerial Ace, attacking Squirtle.
Squirtle uses Hydro Pump, so Ninjask counters it with Sandstorm. Ninjask uses Sand Attack, giving Squirtle a haze in the eyes. Ninjask uses Aerial Ace, but Squirtle hears where it is coming from and evades, using Hydro Pump to attack, but misses. Ninjask uses Aerial Ace again, but this time, the water from Hydro Pump washes the sand from Squirtle's eyes and Squirtle counters with Skull Bash, defeating Ninjask. Brandon calls it back and sends Solrock. Squirtle uses Hydro Pump, but is canceled by Psywave. Squirtle charges with Skull Bash, but is stopped and thrown away by Confusion. Solrock uses Shadow Ball, but Squirtle uses Hydro Pump to go against the wall to evade the attack. Squirtle uses Rapid Spin, but misses and Solrock uses SolarBeam to hit Squirtle. Squirtle is defeated and Ash calls it back. Meanwhile, Team Rocket are digging a tunnel to surprise everyone.
Ash sends Bulbasaur. Solrock uses Psywave, but Bulbasaur dodges and retaliates with Razor Leaf. However, Bulbasaur uses Confusion and sends the leaves back to attack Bulbasaur. Solrock uses Confusion once more, affecting Bulbasaur and sending it to a wall, but Bulbasaur gets out of its control. Solrock uses Shadow Ball, but Bulbasaur evades and uses Leech Seed. Solrock is affected, so it uses Psywave to attack Bulbasaur. Bulbasaur and Solrock use SolarBeam and launch, resulting in both Pokémon to be defeated. Team Rocket comes out of the tunnel and sees the lights turning on - Registeel and Regirock come and use Lock On, then follow with Hyper Beam to blast them off. Brandon and Ash recall their Pokémon. Ash sends Pikachu and Brandon his latest Pokémon he captured - it is Regice.
Pikachu uses Thunderbolt, attacking Regice. Regice retaliates with Blizzard, freezing the battle field. Pikachu uses Iron Tail, so Regice uses Ice Beam and though Pikachu evaded, a part of the battle field is frozen. Pikachu uses Quick Attack, but is stopped by Regice's Ice Beam. Due to the last attack, the entire battle field is frozen. Regice uses Focus Punch, so Pikachu uses Thunderbolt to attack, paralyzing it. Pikachu uses Iron Tail, hurting Regice. Regice uses Ice Beam but misses. However, this makes some ice columns coming out and Pikachu is trapped. Regice rests, so Pikachu uses Iron Tail to free himself and charges. Regice is healed and uses Ice Beam, freezing Pikachu. Ash tells Pikachu he cannot give up and orders a Thunderbolt, but nothing happens.
Samuel goes to declare Brandon a winner, but Pikachu bashes the ice and hits Regice, paralyzing it. Regice uses Focus Punch, hitting Pikachu. Pikachu uses Iron Tail, twice in a row. Regice uses Ice Beam and Pikachu dodges, but is (again) trapped. Regice rests again, so Pikachu uses Iron Tail to get free and charges with a Volt Tackle. Regice is renewed and uses Ice Beam, but misses and Pikachu hits Regice, defeating it. Because of this, Ash wins the battle. Brandon calls Regice back and tells Ash he fought with his own style and gives him the Brave Symbol. Later, Scott presents Ash the plaquette, marking him as one of the Hall of Fame. Scott proposes Ash to become a Frontier Brain, but Ash declines, telling him there are a lot of things to see and do. Scott tells him they will be here if he changes his mind. Brandon and Samuel depart, and so have to Bulbasaur, Squirtle and Charizard, who are needed elsewhere. Ash tells them goodbye until next time they will see each other.
- Background music from Jirachi: Wish Maker, the TV cut of Battle Frontier, and background music from Lucario and the Mystery of Mew are used as background music.
- The next episode preview is narrated by Ash and May.
- The dub episode title is a pun on the famous phrase "Space, The Final Frontier" from the Sci-Fi series Star Trek.
- This episode marked the second time one of Ash's Pokémon defeated a legendary Pokémon. The first was in The Symbol Life with Charizard defeating Articuno.
- Also, both of the legendary Pokémon beaten in these two episodes were Ice-type Pokémon that are part of a legendary trio.
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.