Monkey D. Luffy is the protagonist of Eiichiro Oda’s One Piece series. Intending to become the Pirate King, Luffy set out to sea in an era where pirates are on the rise. To attain this title, Luffy has had to become stronger with every obstacle that he’s faced.

Over the years, Monkey D. Luffy has gained several new powers as he crushed his enemies and right now, he’s one of the strongest people in the entire One Pieceworld. His journey certainly hasn’t been easy, however, and he has struggled against quite a few opponents so far.

Updated February 23, 2022 by Rei Penber: Monkey D. Luffy has been in countless fights over the years and while battles may come easy to some protagonists, for Luffy, they’re often difficult to conquer. This always adds an extra edge to Luffy’s fights and makes them enthralling to watch. While this list already mentions the ten toughest fights Luffy has been in, there are certainly more where he’s struggled to take his opponent down. With that in mind, we’ve made four more additions to the list.

Note: This list doesn’t indicate the strength of his opponents, but rather the difficulty of the fights he fought.

14 Kuro

  • Fight Begins: Episode 15

Luffy’s fight against Kuro was quite a challenge for him, especially when it came to dealing with the incredible speed the latter possessed. While Luffy was successful in landing quite a few hits on him in their fight, once Kuro tapped into the power of the Nuki Ashi technique, it became difficult for him to overcome the obstacle.

After taking quite a few hits from him and getting used to his speed, Luffy was eventually able to predict his movement pattern and counter effectively. While Kuro might not be the hardest fight he’s fought, he’s certainly one who gave him a lot of trouble quite early into the series.

13 Don Krieg

  • Fight Begins: Episode 27

Don Krieg was the captain of the Krieg Pirates and commanded the Krieg Armada, the biggest known force from the East Blue. During the Baratie arc, Krieg fought against Luffy in an enthralling battle and fared quite well.

Although not the strongest, he possessed an arsenal of weapons that made him quite dangerous. Don Krieg had access to an overpowered battle spear that gave Luffy quite a tough time, along with the MH5 gas. Although Luffy won this fight, it required every bit of his energy to overcome Krieg.

12 Gecko Moria

  • Fight Begins: Episode 372

Gecko Moria was the main antagonist of the Thriller Bark arc and one with a bounty of 320 million berries which, at the time, surpassed even Luffy’s own. Moria was quite a troublesome opponent for Luffy to deal with. During their fight, he made clever use of techniques such as Brick Bat to keep Luffy engaged.

At his strongest, even Gear Second wasn’t enough to defeat him so Luffy had to combine Gear Second with Gear Third for the very first time. At the expense of his life force, Luffy was ultimately able to take Moria down but not before passing out from exhaustion himself.

11 Enel

  • Fight Begins: Episode 182

The God of Skypiea, Enel was the main antagonist of One Piece’s Skypiea arc. With the power of the Goro Goro no Mi, he was practically invincible against everyone there, except for Luffy, who could resist his lightning powers due to his Gomu Gomu no Mi powers.

Despite being at a clear disadvantage, Enel was able to defeat Luffy once. His mantra, along with his tactical prowess in battle made him quite a foe for anyone. In the end, Luffy had to seek help from all those around him to take Enel down.

10 Sentomaru

  • Fight Begins: Episode 403

Sentomaru made his One Piece debut during the Sabaody Archipelago where he fought Luffy and managed to cause him all sorts of trouble. With incredible defense and a Haki that was especially strong, Sentomaru was able to take the brunt of the force that Luffy threw his way and counter effectively.

With his Ryuo, he could damage Luffy quite severely and, for the first time, make him consider running away from a battle. Sentomaru might not have given fans the flashiest of battles but he certainly gave fans one that saw Luffy struggle quite a lot.

9 Pacifista

  • Fight Begins: Episode 401

On Sabaody Archipelago, the Straw Hat Pirates were introduced to the Pacifistas for the very first time. Surprisingly, it took the combined effort of the entire crew to fight them. Luffy, who played quite a big role in the battle, wasn’t able to defeat any of them by himself.

Eventually, the crew managed to defeat the Pacifista but not before Luffy was exhausted after repeatedly using Gear Second and Gear Third. Without a doubt, the Pacifista caused all sorts of trouble for him in battle.

8 Donquixote Doflamingo

  • Fight Begins: Episode 721

Also known as the Heavenly Demon, Donquixote Doflamingo was the main antagonist of One Piece’s Dressrosa arc. Being a Shichibukai, Doflamingo was quite difficult to take down in battle and he held the upper hand in the fight against Luffy for the longest time.

However, once Luffy went Gear Fourth, Doflamingo was absolutely no match for him. Even then, Luffy’s lack of energy made this fight even harder for him as he needed ten minutes to regain his Haki and thus, survive. By using his strongest attack, Luffy was ultimately able to defeat him.

7 Charlotte Cracker

  • Fight Begins: Episode 798

Charlotte Cracker is one of the Three Sweet Commanders of the Big Mom Pirates and has a bounty of 860 million berries on his head. Cracker was incredibly difficult for Luffy to fight as his Armament Haki was quite powerful.

Just one biscuit soldier created by Cracker required him to go Gear Fourth, which just goes to show how strong he was. Even when Luffy used Gear Fourth multiple times, he couldn’t defeat Cracker in combat. It was only when Nami helped him that he was finally able to take down the Sweet Commander.

6 The Three Admirals

  • Fight Begins: Episode 474

Luffy fought the Three Admirals during the Marineford arc of One Piece and was obviously no match for them. However, he had no choice but to fight them or Ace would’ve died.

The Admirals didn’t take him seriously and didn’t even use their full powers against him. Luffy was subdued pretty quickly but was always saved by those around him, such as Marco, allowing him to escape from them every single time.

5 Charlotte Katakuri

  • Fight Begins: Episode 852

Katakuri was the strongest of the Three Sweet Commanders of the Big Mom Pirates and he fought Luffy towards the end of the arc. The two engaged in a gruesome battle in the Mirro World where Katakuri absolutely dominated Luffy.

Surprisingly, Luffy picked up the ability to see the future during this fight and thus leveled the field. After taking quite a beating for twelve hours, Luffy finally went all-out using Gear Fourth: Snakeman and defeated the strongest opponent that he had faced at that point.

4 Sir Crocodile

  • Fight Begins: Episode 110

Sir Crocodile was the main antagonist of the Alabasta arc of the series and the first Shichibukai that Luffy took down. Crocodile is easily one of the most difficult fights that Luffy has ever fought as he lost to him twice.

In fact, Luffy would’ve died both the times had luck not been on his side. He was saved from a near-death state by Nico Robin outside of Rain Dinners and later, by his sheer luck in Alubarna. Even during their last fight, Crocodile poisoned him heavily and Luffy was on his very last legs throughout the battle.

3 Rob Lucci

  • Fight Begins: Episode 294

The main antagonist of the Enies Lobby arc, Rob Lucci was quite a challenge for Luffy. The two clashed initially in Water Seven and the Straw Hat captain was completely outclassed by him in combat.

In Enies Lobby, Lucci once again held the upper hand even when Luffy gained two new powers in the form of Gear Second and Gear Third. Eventually, it was the motivation to save Robin that pushed Luffy beyond his limits and allowed him to defeat Lucci.

2 Magellan

  • Fight Begins: Episode 435

Magellan is the Vice-Warden of Impel Down and before the time skip, he held the position of the Warden. He clashed against Luffy in the fourth level of Impel Down, known as the Burning Hell.

Magellan was way stronger than Luffy and was able to easily overpower him in battle. Although Luffy managed to bring him to his knees, he was unable to take him down and ended up almost dying in the fight.

1 Kaido

  • Fight Begins: Episode 914

Kaido is one of the Yonko of the One Piece world and the man called the “Strongest Creature” in the story. In the Wano Country arc, Luffy confronted Kaido quite early on and even though Kaido was drunk, he wasn’t able to inflict even a single injury on him.

When the Yonko sobered up, he took Luffy down in a single blow of his club, showing the true power of a Yonko. After training for quite a long time and acquiring Ryou, along with learning how to use Conqueror’s Haki, Luffy once again took Kaido on in battle but lost yet again. The two are currently still engaging in their third fight and it appears to be quite even at the moment.