Thor is taken through a tunnel introducing the Grandmaster. He begins to panic when the tunnel ends and he is jolted into a meeting with the Elder himself was an eccentric man in colorful clothing, with an assistant beside him.
Thor reunites with Loki, who reveals that he has been on Sakaar for weeks. He distances himself from Thor so as to maintain favor with the Grandmaster. Thor is thrown into the slave quarters, where he meets two of the slave gladiators - Korg, a Kronan, and Miek, an insect alien with knives for hands. Korg introduces himself, and talks to him about the revolution he tried to start, and the Grandmaster's champion.
Loki and the Grandmaster arrive at the Sakaaran Arena to witness the fight. Thor enters the arena, putting on his helmet and picking up his weapons as he prepares to engage his contender. The Valkyrie watches the arena from her ship above.
The Grandmaster introduces Thor, and the audience begins to call out for their favorite combatant, the champion. As the Grandmaster turns to introducing his champion, his call is cut short as the combatant breaks into the arena, revealing himself to be the Hulk, alive after his disappearance 2 years prior, but angered, crazed, and ready to battle. Thor, overjoyed at seeing his former teammate, attempts to talk and negotiate with him, but makes the mistake of calling him "Banner". As he watches, Loki becomes nervous and uncomfortable after seeing the Hulk, following their last encounter after the Battle of New York. Refusing to acknowledge Thor, despite his pleas and attempts to make him calm down, Hulk fights against his former ally, smashing Thor into the arena wall before throwing his hammer at him, which narrowly misses Thor's head. However, Thor turns the tables with this, grabbing the hammer as Hulk charges at him again and smashes him across hard across the arena wall, much to the shock of the Grandmaster and spectators.
Thor tries Black Widow's calming technique on the Hulk, but it fails to work; Hulk smashes Thor around similarly to how he smashed Loki around in Avengers Tower, much to Loki's pleasure, gloating that now he knows how that feels. Frustrated at being unable to reach his former ally, Thor goes on the attack, hitting him several times with Hulk's hammer, destroying Hulk's battle axe in the process; however, this only further angers his opponent, who, after taking several more hits, disarms Thor and sends him flying across the arena before repeatedly hitting Thor's face into the floor.
Just as it looks like Thor is about to die, he suddenly has a vision of his father, causing his lightning powers to surge, and hits the Hulk with a large bolt of lightning, sending him flying through the air. Thor continues to re-gain the upper hand, hitting Hulk with a lightning-powered punch, gaining the support of the spectators and the other gladiators, who are watching from their quarters. However, unwilling to see Hulk lose, since he is a fan favorite, the Grandmaster cheats and fixes the fight by activating the Control Disk on Thor's neck, incapacitating him. Hulk attacks Thor and leaves him unconscious.
After their fight, Thor wakes up in Hulk's chamber. The two former allies have a conversation, and Thor keeps pleading for Hulk's assistance, but Hulk refuses to acknowledge their friendship, grumpily stating that Thor likes Banner better. He does, however, reveal the location of the Avengers' Quinjet, nearby on Sakaar. Despite Hulk knocking Thor unconscious, Thor insists that he won the fight; he later recounts their fight to Bruce Banner after eventually forcing Hulk to revert back, saying he won easily, though Banner is not entirely convinced that this is true.