Battling a Thaw in Relations! (Japanese: 決着ライバルバトル！サトシ対シンジ！！Conclusion of Rival Battle! Satoshi vs Shinji!!) is the 188th episode of the Diamond & Pearl series, and the 654th episode of the Pokémon anime. It first aired in Japan on August 19, 2010, and in the United States on January 15, 2011.
The episode begins right where it left off, with Gliscor diving towards Drapion with an X-Scissor attack. It is subsequently blocked by Drapion's Pin Missile at the last moment, sending Gliscor flying back and landing on the ground. When Paul instructs Drapion to use Cross Poison, Ash calls out to Gliscor to use Fire Fang, and Gliscor is all ready to go. It jumps up, dodging the Cross Poison along the way. Gliscor lands the Fire Fang attack, which envelops Drapion in fire for a moment. Paul does a quiet growl at this while Ash grits his teeth with hope. Drapion then subsequently fainted, thus leaving Paul with one final Pokémon. The gang decides to cheer him on, but Brock reminds everyone that while Ash may have three Pokémon left, they've all taken damage as opposed to Paul's final Pokémon who has yet to enter the battle.
Ash decides to call back Gliscor when Paul sends out his final Pokémon which is none other than Electivire, the only Pokémon on Paul's current team that Ash has battled before. Gliscor lets Ash know it can still battle, so Ash decided to leave Gliscor in given that it has a type-advantage over Electivire. Paul tells Electivire to start by using Thunder and directing it into the ground. Electivire sends its tails into the ground and directs Thunder into it, which sends chunks of the earth up into the air and falling onto Gliscor. Brock realizes that Paul thought of this strategy as a result of Infernape using Flare Blitz underground earlier. Ash tells Gliscor to use Giga Impact and Electivire blocks the attack with its hands and catches Gliscor with its tails. Ash tries to call out a command, but Gliscor is unable to make an attack. Paul tells Electivire to use Brick Break on Gliscor, and it lands on Gliscor's head, causing it to faint. Thus, leaving Ash with two Pokémon, Pikachu and Infernape.
Ash sends in Pikachu next, and Paul tells Electivire to direct Thunder into the ground again. Once again, the ground erupts and rocks are sent flying to towards Pikachu. However Pikachu is ready and uses Quick Attack to dodge the falling rocks, even using some of them for momentum, and lands a direct hit on Electivire causing damage. However, Electivire recovers and grabs Pikachu with its tails and when Pikachu tries to use Iron Tail, Electivire jolts Pikachu around so that he can't land the attack. Pikachu hits the ground, but is able to escape the pseudo-Constrict by Electivire's tails. Paul tells Electivire to use Brick Break, and Pikachu tries to prevent the attack from happening with Quick Attack, but Electivire lands the attack dead-on. The two Pokémon jump back after clearing the impact. Ash tells Pikachu to use Volt Tackle, sending Reggie watching from a television in Veilstone City and Barry to stand up, knowing that this was a bad move on Ash's part. Paul, knowing what is about to happen, tells Electivire to block. Electivire holds out its arms as Pikachu lands Volt Tackle, and the attack is so powerful that electricity lights up the entire stadium. As Pikachu lands and is damaged by the recoil, Electivire starts to speed up thanks to its Motor Drive Ability (which increases Electivire's speed when hit by an Electric-type attack, such as Pikachu's Volt Tackle). Paul tells Electivire to use ThunderPunch, and Electivire speeds forward so fast it can barely be seen and prepares to strike. However it seems Ash anticipated this, and actually allowed the speed boost to draw Electivire in. Ash tells Pikachu to use Iron Tail at the last moment and the two attacks collide together. However, the strategy has backfired on Ash as Pikachu is left unable to move. Paul recounts his and Ash's first battle when Pikachu was battling Elekid, and how Ash wanted Pikachu to get close so he could finish the battle with Iron Tail. Paul tells Ash that this time Pikachu's stuck and if it lets up even a little, it will be overcome by ThunderPunch. Ash knows Electivire can still use a move with its left hand: Brick Break. Paul tells Electivire to use Brick Break, and as Electivire powers up its fist Ash tells Pikachu to try and hold on. Brick Break lands directly on Pikachu's head, sending him flying. Pikachu tries to get up after landing from the fall but it turns out to have been too much and Pikachu faints, leaving Ash with one Pokémon left, Infernape. Ash puts Pikachu behind him, and thanks him for his hard work.
Ash sends out Infernape. Electivire and Infernape have a long standing rivalry, even from the Chimchar-Elekid days. Jessie, James and Meowth are busy stuffing their faces, watching this intense battle, when they should be selling the food. Electivire starts things out with a ThunderPunch and Infernape counters with Mach Punch, and the two attacks collide and neutralize each other. Infernape uses Flamethrower, which is blocked by Electivire's Protect. Electivire uses Thunder to create a Counter Shield around the battlefield, but Infernape uses Dig to travel underground and avoid the attack. Infernape surfaces below Electivire and hits it dead-on, but then takes damage from the poison it received earlier. Electivire manages to stand up. After yet another blocked Flamethrower, Infernape and Electivire start attacking with Mach Punch and ThunderPunch, respectively continuously. They both each land an attack before another Flamethrower by Infernape is blocked by Electivire's Protect. Ash instructs Infernape to use Mach Punch, but Electivire dodges it and wraps its tail around Infernape's arm. Reggie still watching the battle pleads Ash not to fall for that trick again. It uses Thunder while Infernape is connected to it, causing more damage than a normal Thunder attack. It continues to use Thunder on Infernape for a long time.
Infernape collapses to the ground when Electivire finally lets it go. As it has taken a severe beating throughout the match, the gang, Barry, Piplup and Team Rocket are all desperate for Infernape to get up but it appears to have been too much. The referee begins to declare Infernape unable to battle... when Electivire interrupts him, knowing that Infernape still has the ability to fight and wants to finish the battle properly. Paul tells Infernape that he thought it had gotten stronger, but once again all it has managed to do is disappoint him before he turns away as if to leave...
Infernape suddenly regains its senses and Ash responds to Paul 'fraid not!'. Much to everyone's (except Ash's) surprise, Infernape stands, and Ash declares that it's time to show Paul just how strong Infernape has become as it activates its Blaze. Reggie realizes Ash must have wanted that Mach Punch thrown earlier to miss on purpose so he can have Infernape unlock its true power. Ash orders a Flamethrower, and Infernape fires a super-powerful blast at Electivire who tries to hold it back with Thunder but can't stand up to the sheer power. Ash then has Infernape use Mach Punch which hits and sends Electivire flying but it still lands on its feet. Now both fully absorbed in the intensity of the match, Paul screams for a ThunderPunch while Ash orders Infernape to use Flare Blitz. The two Pokémon, battling to the limits of their power, land their attacks against the other which creates a maelstrom of fire and electricity streaming into the sky, illuminating the stadium. Eventually Infernape ends up on the other side of Electivire, feeling the recoil from Flare Blitz, causing its fiery crown to do severe damage to Electivire, who, after a delayed reaction, feels the force of the power attack. The smoke clears, but Electivire is still standing and the two Pokémon stare each other down... as do their Trainers as a deathly silence falls over the battlefield. The two Pokémon remain perfectly still for what feels like an eternity... until, finally, Electivire falls and is declared as being unable to continue, making Ash the victor of this truly intense battle. Dawn, Piplup and Barry scream out in elation for Ash's victorious win over Paul while Brock is overwhelmingly pleased. Team Rocket is elated Ash won, leaving Jessie happy and James in tears. Then, they remembered they accidentally ate all the food, while during the battle. Paul thanks Electivire for its hard work. As Paul is about to say something, Infernape almost fell but got held by Ash. Paul walks away relieved and the pairing results for the next battle come up, pairing Ash with the mysterious Tobias and his Darkrai. Tobias saw the screen and walked away. Back in Veilstone City, Reggie delivers the news to Paul's other Pokémon, who are sad Paul lost but happy that he gave it his all.
Later, Brock and Dawn are walking outside and run into Barry, where they are all looking for Ash. Then, Cynthia comes forward, and Barry is awestruck at being face-to-face with the Champion. Cynthia explains that although Ash and Paul are very different people and may never truly be friends, all their time feuding and battling with each other has created a bond between them that can never be broken. Both have learnt a lot from each other and have both become far stronger as a result...
"When one life meets another life, something will be born."
Cynthia finishes by telling everyone that she is eager for the day when Ash or Paul make it all the way to the Champion League so she could face them in battle properly.
Paul is about to leave Lily of the Valley Island when Ash calls out to him. Paul finally admits that Infernape is strong and Ash has done a great job in raising it. Ash asks if Paul is leaving already, which Paul confirms as there is no reason to stay. He will be heading back to Snowpoint City to request another battle with Brandon. Ash wishes him good luck with that, while Paul wishes Ash good luck on the rest of his Pokémon journey. Paul turns to leave, and Ash tells Paul that they will battle again really soon. Paul signals a goodbye to him, letting his rival know that he has earned his respect and bringing their long-standing rivalry to an end. As Paul leaves, Ash considers the events of the day. He has won his most important and intense battle ever, but now, he has an even bigger challenge to face, his next opponent, Tobias and his powerful Darkrai...
As of this episode, this is the first time that a single battle has spanned more than two consecutive episodes.
The battle also had the most Pokémon affected with status ailments ever in just one battle in the anime, with two Pokémon getting burned, five being poisoned and two (counting Buizel's Ice Aqua Jet) being frozen.
When Infernape uses Mach Punch on Electivire while Blaze is active, for a split second, Infernape looks as if it doesn't have its Blaze active.
In one scene, Ash's Diamond and Pearl hat looked like the one he wore in Hoenn.
When Electivire uses Thunder on Infernape, the red part of Electivire's tail was pink.
In Familiarity Breeds Strategy!, the announcer declares Paul and Ash's match the first match of the quarter-finals, and all of the quarter-final, semi-final, and final matches are fought on the same field. Yet at the end of the match, the pairings for the semi-finals are already revealed on screen without scheduling.