In One Piece, there is a standard convention where power reigns supreme. Usually, the individual that can punch the hardest will win a fight regardless of how crafty their adversaries are. This has become especially true in the later acts of the series when armament haki was introduced.
However, there have also been numerous instances to the contrary. Whether exploiting a particular weakness or using the environment to their advantage, some characters have managed to defeat significantly stronger opponents by outwitting them. Through identifying examples, it becomes easier to appreciate the value of a sharp mind and even disposition.
10 Nami Used Kalifa's Own Power Against Her
Kalifa's power allowed her to weaken enemies by cleaning them to absurd degrees. However, once Nami realized that her opponent relied on water, she used it to her advantage. Through drying herself off and carefully using her lightning rod, she defeated the agent and rejoined her friends.
This is especially impressive when considering that Kalifa has dramatically greater strength, durability, and speed than Nami on top of her existing CP9 abilities. Should Nami not have identified Kalifa's elemental counter, she never would have stood a chance.
9 Luffy & Nami Teamed Up To Defeat Cracker
Charlotte Cracker's baseline abilities were overpowered. He could summon hardened biscuits in massive swathes and they were only defeated by Luffy's Gear 4. However, Nami was present to assist her captain in battle.
By using her rain tempo, she softened the biscuits enough for Luffy to eat. Not only did this grant him an enormous burst of energy, it deprived Cracker of his minions, effectively rendering him powerless. Once Luffy realized his weakness, the villain was quickly defeated regardless of the additional constructs he summoned.
8 Kaido's Subordinate Distracted Oden During Their Fight
Surprisingly, Oden got the upper hand on Kaido during their battle for Wano. Despite the dragon's immense size and firepower, the hero ignored his attacks and delivered a devastating scar. However, one of Kaido's subordinates took on the likeness of Momonosuke in order to distract Oden.
As a result, Kaido had the opportunity to swing the battle back in his favor and take out his target with a surprise attack. Oden's defeat heralded the end of Wano's resistance, with the Scabbards being scattered in all directions shortly afterward.
7 Luffy Capitalized On Crocodile's Logia Weakness To Defeat Him
At first, Luffy had his work cut out for him against Crocodile. Without armament haki, it was exceedingly difficult to damage the villain's logia body even with access to water. During their final confrontation at the crypt, Luffy used his own blood to harden his knuckles and make them viable weapons.
This caught Crocodile off guard, who had previously assumed his opponent to be just as helpless as the first time they fought. Nonetheless, Crocodile's overconfidence resulted in his defeat and the total liberation of Alabasta. It was also the first of many disgraces to the Seven Warlord program.
6 Luffy & Galdino Worked Together To Halt Magellan
Magellan's Devil Fruit allowed him to secrete noxious poisons. Even the slightest exposure could kill its target, a lesson Luffy learned during their first fight. However, since Magellan did not have a logia power, Luffy could still injure him.
As a result, he had Galdino construct him a suit of wax that he used to batter the Jailer while his friends escaped. Though Luffy did not knock Magellan unconscious, he managed to fulfill his goal of fleeing Impel Down.
5 Sanji Turned Kuroobi's Physiology Against Him
Kuroobi thwarted Sanji's attempt to save Luffy by attacking him underwater. Considering the fish man's prodigious size and strength, Sanji could not effectively wriggle himself free and return to the surface for air. Luckily, he didn't need to.
By covering Kuroobi's gills, he forced his opponent to resurface and put them on even footing. In a straightforward land fight, Sanji dominated Kuroobi without much difficulty regardless of his opponent's "fish-man karate" techniques. This further enabled Luffy's escape and revitalized the effort against Arlong's monstrously amphibious forces.
4 Blackbeard Waited For The Right Time To Kill Whitebeard
Despite obtaining his darkness fruit and a crew of deadly convicts, Blackbeard knew that he still wasn't a match for Whitebeard. As a result, he positioned himself as a warlord of the World Government and waited for the Marineford war to reach its climax.
After Whitebeard had been betrayed, shot hundreds of times, and pumped full of magma, Blackbeard entered the fray to finish his former captain off. He emerged from the conflict with Whitebeard's Devil Fruit, rendering him one of the most powerful men alive.
3 Hody Jones Used The Environment To Defeat Zoro
By his own merits, Hody Jones was not strong enough to defeat Zoro. Fortunately, the environment worked to his advantage. By breaking Neptune's castle and overwhelming Zoro with henchmen, Hody made sure that the swordsman drowned even despite the injuries he accrued in the process.
When Zoro woke up, he was imprisoned alongside Usopp and Brook. Fortunately, the latter managed to retrieve his swords, allowing him to slice his way out of prison and rejoin the fight. Hody's biggest mistake was not killing Zoro when given the chance.
2 Brook Capitalized On The Oniwabanshu's Superstition
The Oniwabanshu were an organization of shinobi in service to Orochi. After Robin's role as an infiltrator had been revealed, they hoped to corner her and torture her for information. Fortunately, Brook was nearby to save the day.
He used his spiritual form to terrify his enemies and capitalize on their highly superstitious nature. As a result, he scattered them in all directions and saved Robin's life all without suffering a single injury. Brook's victory is somewhat ironic when considering that his opponents could have defeated him if they worked together.
1 Luffy & Bege's Crews Humiliated Big Mom At Whole Cake Island
Though the operation to kill Big Mom was technically a failure, Luffy and his friends gained much from the encounter. He copied her poneglyph, saved Sanji's family, and humiliated her on the global stage. His success was especially impressive since Big Mom benefited from the protection of her children.
The Straw Hats only won by understanding Big Mom's weaknesses. They destroyed a picture of her adoptive mother to put her in an emotional state and deprived her of the wedding cake to make her hungry. Both actions left the emperor significantly weaker than she would have been otherwise.