Fans were shocked when Thanos beat up The Incredible Hulk in the opening scene of Avengers: Infinity War. The brutal beating established Thanos as a powerful opponent with superior fighting skills as even the Hulk appeared scared to face the Mad Titan again. Even so, some audiences thought the fight was unfair. Thanos had already acquired the Power Stone, after all, which gave him access to a limitless source of physical strength that outmatched even the Hulk. Without the stone, some fans felt the Hulk would have a definite edge.
Except… he probably wouldn’t. In the comic book miniseries that Avengers: Infinity War was based on, Thanos actually battles and defeats an opponent infinitely more powerful than the Hulk. Moreover, that opponent is the one wielding the Power Stone, not Thanos!
The clash takes place in the first issue of Thanos Quest, which followed Thanos’ attempts to acquire all six Infinity Stones (called “Soul Gems” or “Infinity Gems” in this storyline). Thanos acquires the Soul Stone (or Gem) first from a creature known as the In-Betweener. He then turns his sights on the Power Gem, which he believes will provide him with the limitless power he requires for his next few tasks. Of course, to acquire the Power Gem, Thanos needs to face off against its keeper – a brutish immortal being known as the Champion.
Tracking Champion to the planet Tamarata, a world constantly under siege by warring federations, Thanos finds the all-powerful being beating up entire armies by himself. Such actions are typical for Champion, who is only interested in testing his might against incredibly powerful foes (not unlike Goku of Dragon Ball Z). Thanos takes advantage of this by challenging Champion to a fight, which the battle hungry being eagerly accepts. Right from the start, however, it’s clear Thanos is in complete control of the battle. While Champion is much stronger than Thanos, his movements are brutish and Thanos is able to dodge his blows and knock him off balance. He also employs technology against Champion, shielding himself with a powerful force field. These attempts enrage Champion, who decides to take down Thanos with an all-powerful blow by leaping several miles straight up – and then coming down on Thanos with the power of a nuclear bomb… which is exactly what Thanos wants.
Moments before Champion can strike, Thanos teleports himself away, causing Champion to hit the ground and create an explosion that starts a chain reaction which literally shatters the entire planet. Realizing that Champion had unknowingly been drawing on the infinite reserves of power from his Power Gem, Thanos intentionally goaded his opponent into releasing that power into his world – leaving him adrift in space.
Initially, Champion is elated that he won – until Thanos points out that, without a ship to transport him through space, Champion will just drift aimlessly for centuries. Realizing that Thanos is right, Champion begs the Mad Titan to take him to another planet, which Thanos agrees to do – in exchange for Champion’s Power Gem. He then honors their agreement by dragging Champion to another planet with his tractor beam, but makes sure he falls through the atmosphere to get there since he never agreed to give Champion “a soft landing.”
While audiences never got to see how Thanos acquired the Power Stone in Avengers: Infinity War, his acquisition of it in The Thanos Quest is a stunning display of strategy, guile, and sheer brute strength. Powerful as Thanos is, he didn’t have the strength to take down Champion in a fair fight – so he didn’t try to. Using his superior knowledge of Champion’s abilities, Thanos manipulated Champion into using his own power to his disadvantage, ensuring a win for Thanos. Given what happened to the planet, the Hulk probably has plenty to worry about if he ever goes up against Thanos again.