The Marvel comics establish the Hulk as possessing limitless physical strength and endurance, which could easily withstand a few (if not all) of Saitama's punches.
Sometimes the best battle fought is one that isn't fought at all. Light Yagami's Death Note is the ultimate weapon he has with him. Basically, all he has to do is lift his fingers, jot down Saitama's name, and Saitama would be dead.
Thanos has the infinity gauntlet with all six infinity stones (gems). If he “retires”, like like he does after snapping away half of life (movie Infinity War), then he is no longer in possession of the six infinity stones powers, and will definitely not be able to beat Saitama.
Even if Goku was able to use his highest form of power, Saitama's one-punch certainty means a fight wouldn't last for long. If we are to take Saitama's power and accuracy at face value, it almost doesn't matter who his opponent is — he would win outright.
Given this premise, in a straightforward one-on-one physical battle, Saitama, aka One-Punch Man, would likely emerge as the victor, as his power is portrayed as limitless and invincible.
In a battle against Hulk, every little bit counts. Saitama having this ability provides him a slight edge, as he effectively has a source of projectile attacks that he can use at a distance.
Shonen Jump heroes are generally known for their ridiculous strength; however, One-Punch Man's Saitama is on a completely different level. Renowned for being able to end almost any fight in one punch, he just might be able to defeat Naruto — or any other shonen protagonist — in a one-on-one fight.
Beerus, no question. Saitama's best feats (getting kicked to the moon and jumping back to earth, splitting a life wiping energy beam, destroying a giant meteor etc) would barely place him at Namek Saga levels by DB standards.
He was stated to have infinite potential which basically means he'll get stronger everytime he trains or engages in a good fight. Here, the only way Saitama can even beat Vegeta is if and only if Vegeta decides to go easy on him or play around with him & eventually Saitama surpasses him.
It's been shown many times that a wizard can dodge spells. So Saitama would have no trouble remaining untouchable in their fight as he is even faster than Speed-o'-Sound Sonic. If he can jump off the moon and land back on earth in a couple seconds, he would have no trouble winning.
Will he able to destroy it with One Punch? He would find he can't lift it. At best Saitama has demonstrated planetary levels of strength with ease. However, Mjolnir is not something you can lift via strength.
Garou's Gamma Ray Burst (which is said to be the most powerful and destructive natural phenomenon in the universe) and nuclear explosions had all proved ineffective against Saitama even though they both possessed an amount of radiation that would be very fatal to normal humans.
If we take into account what we've seen in Loki's journey, him becoming the God of Stories, he actually might be stronger and more durable than Saitama in those terms.
As Dragon Ball Ki operates the same for defense as it does offense, then Krillin's signature technique would let him deal a fatal blow to Saitama, who has yet to show power or durability on that level. And anyways, the Destructo Disk's whole selling point is how it can harm opponents far above Krillin himself.
Saitama is a man that can defeat any foe with a single punch. If the two of them were to face off in a one-on-one battle, Saitama would easily win. The fight wouldn't last a second let alone enough time for Goku to transform into a Super Saiyan.
The Uchiha clan is strong when it comes to Illusions/Genjutsu, he is also able to rip out a soul with his rinnigan. But Saitama is just far stronger, and he can survive more than Sasuke… Saitama has shown immunity to mind hax/spirit hax, Depends on the rules of the Universe.
Saitama's abilities come exclusively from his physical might. They have absolutely nothing to do with technique or chakra flow. So Kakashi trying to copy that would just result in him copying a basic punch that does no more damage than a regular Kakashi punch.
The battle between Saitama and Thanos was intense and destructive, but ultimately, Saitama's immense strength and speed proved to be too much for even the all-powerful Thanos with all six Infinity Stones.
Both combatants were incredibly strong and fast, but when you look at the numbers, Juggernaut had a clear advantage. Boomstick: He basically took it in every category, besides smarts. His feats of beatin' up Hulk far outclass anything Saitama's ever done.
