Ash Ketchum from the Pokémon anime has traveled across the land, searching far and wide. Pokémon battling has been Ash's number one passion from the very beginning, and with 25 years of adventures under his belt, he's had some incredibly intense and meaningful fights over his career.
Whether he's winning or losing, his battles are often much more than just simple competition. Ash's greatest battles in the anime tell engaging stories, develop both Ash and his opponents, include unique, creative strategies, and symbolize his relationships with people and Pokémon alike.
10 May Proved Herself An Equal To Ash
Pokémon Contests were a popular subplot introduced in the third generation, serving as the goal for several of Ash's companions. Ash and May compete in an unofficial Contest at the end of Advanced Generation, which ultimately ends in a draw.
The battle is already engaging for featuring a starter battle between Sceptile and Blaziken, but most importantly, it represents May and Ash's student-mentor relationship. Now an equal to Ash, May fights his Hoenn ace to a standstill in a match that deeply respects both characters' goals.
9 Gladion Changed The Status Quo Forever
Ash's Alola League battle with Gladion marks one of the most iconic turning points in the anime. Ash winning the League and becoming a Champion flipped the show on its head. It proved the series was done with keeping him in the same cycle over and over.
Although it's not a full six-on-six like Ash's other rival showdowns, this approach ensures no moment is wasted on one of Ash's greatest achievements. Ash and Gladion show off their unique levels of strength by using Legendary and Mythical Pokémon, and share a heartfelt conclusion to their rivalry.
8 Gary Oak Was Ash's Original Rival
It's hard to forget the first major rival Ash ever overcame. Gary was two steps ahead of Ash in the original series, but when it mattered most, Ash finally triumphed over him in the Johto League. Following this, the two settled their differences and became friends.
While the battle isn't as visually striking as its many successors, and suffers from leaving Pikachu out, it's easily the most memorable match-up in the original series. It establishes the template for all rival battles to follow.
7 Brandon Was The Kanto Team's Greatest Victory
Brandon was the final challenge for Ash's Battle Frontier quest, proving to be a threat beyond anything he had faced prior. Having suffered from two previous losses to the mighty Frontier Brain, Ash called upon his longest lasting Pokémon, the three Kanto starters, to aid in their third battle.
Watching Ash's original team members return for a final moment of glory is incredibly rewarding for longtime viewers. Between that and Pikachu's first victory over a Legendary Pokémon, the battle ensured that Advanced Generation went out with a bang.
6 Lake Acuity Devastated Ash In The Best Way
While Ash has had plenty of amazing wins, he's also had many heartbreaking losses. No other loss crushed Ash as deeply as his Lake Acuity battle against Paul, a cruel Trainer who tormented Ash across all of Sinnoh. Despite his nasty attitude, Paul was also brutally tactical in nature with special counters for Ash's team, resulting in a 6-2 loss.
As devastating as it is, the battle serves as one of the most powerful moments of the anime. It gives Paul some much-needed development and forces Ash to reflect on his own methods. Ultimately, it sets up their next battle in the Sinnoh League to be that much more satisfying.
5 Misty Grew Alongside Ash
Misty is the very first companion to ever join Ash on his travels, and stayed with him for the entire original anime. Their long history has formed a special connection between the two of them, and nowhere better is this displayed than their unofficial Gym battle from Sun & Moon.
While the battle is only one-on-one, it captures the deep respect Ash and Misty share while showing how far they've come from their rookie days. It's also just as thrilling as it is meaningful, featuring superb animation, excellent strategies, and a clash between Mega Evolution and Z-Moves.
4 Clemont Was Ash's Most Built Up Gym Battle
Ash and Clemont prepared especially hard for their Lumiose Gym battle. In a unique twist, Clemont briefly left Ash's group to train up for their battle, while Ash had been preparing to battle him since the first day they met.
The battle serves as the climax of Clemont's arc. It features beautiful action, parallels to the first episode of XY, and a heartwarming ending for Ash and his Kalos companions. It's very rare that a Gym battle is built up as thoroughly as this, but it works all the same in ensuring how impactful it was.
3 Professor Kukui Celebrates Ash's Championship
Professor Kukui became the father figure Ash never had during Sun & Moon. Despite their close relationship, Ash and Kukui's mutual love for battle built up a battle between them from the very start. As the reward for winning the Alola League, Kukui has a four-part, six-on-six battle with Ash.
Although there are technically no stakes due to being an exhibition match, it doesn't stop the two Trainers from going completely all out, especially after Tapu Koko joins in. The battle resolves multiple rivalries for Ash's Pokémon, and simply keeps up an infectious level of fun. It's extremely hard not to get wrapped up in both characters having the time of their lives.
2 Leon Is Ash's Most Powerful Challenge
Ash's Masters Eight battle against Leon is the anime's biggest battle by a wide margin. It's one of only two battles in the series to stretch across four episodes straight, and its sheer magnitude is unlike anything from the series prior, with Ash battling for the ultimate spot as the world's greatest Trainer.
Above all else, the final match between Pikachu and Charizard is the ultimate showdown between two lifelong partner Pokémon. All of Ash's friends and Pokémon appear to support him for his accomplishment, and it more than earns its status as Ash's final challenge.
1 Paul Concludes The Anime's Best Storyline
Paul is the ultimate rival and foil to Ash Ketchum. Cold, calculated, arrogant, and rude, he challenges the very core of Ash's belief in raising Pokémon through love and respect. Their greatest battle at the Sinnoh League puts everything they've learned on the line, both about battling and about each other.
No other character was built up for a final clash the way that Paul was. Their Sinnoh League match builds off all their many previous battles, draws countless parallels to past episodes, and ends with Paul's magnificently karmic defeat at the hands of his former Pokémon, Infernape. To this day, Ash vs Paul set the gold standard for every story arc in the anime.