Resolved to fight Grimmjow on even ground, Ichigo asks Orihime Inoue to heal the injuries that were inflicted on them by Ulquiorra Cifer. Ichigo suggests that they settle their fight elsewhere; complying, Grimmjow follows him to a more open area. To prepare for the fight, Ichigo activates his Bankai en route to the battleground. By the time he arrives, Grimmjow is already there, standing on top of a large pillar.
Immediately, they clash blades in midair before bringing the fight down to solid ground, where the force of their attacks tears up the ground around them. As the battle comes to solid ground, Grimmjow leaps back to avoid one of Ichigo's attacks and proceeds to charge a Cero in his free hand. Intending to approach the attack head on, Ichigo prepares to use Getsuga Tenshō. However, as he is calling out the attack's name, Grimmjow throws his Zanpakutō, leaving his other hand free to attack him with another Cero. The force of their two attacks creates a large explosion, separating the two combatants. Laughing, Grimmjow exclaims his excitement over the chance to finally crush Ichigo, and asks if he feels the same way. Ichigo denies it, but Grimmjow accuses him of lying, reminding him that he hurt his friends. He tells Ichigo that he'll teach him why he kept his scar, and declares that he will finally kill him, to prove that he is superior.
Grimmjow quickly retrieves his Zanpakutō, which he had previously thrown into the pillar he was initially standing on. He then leaps on top of the pillar, and criticizes Ichigo for having no killing intent. He then uses Sonído to quickly flank Ichigo, attempting to hit him, but Ichigo manages to dodge him, leading to another series of blade clashes. As their blades are crossed, Grimmjow asks Ichigo what his reason for coming to Hueco Mundo was. Ichigo answers that he did it to save Inoue, but Grimmjow points out that he could have taken her back the moment he saw her. He then accuses Ichigo of relaxing when he saw Inoue uninjured, and of being ignorant of how she must feel on the inside. Believing that Grimmjow is implying that he hurt her somehow, Ichigo angrily demands that he tell him what he did to her. Liking the way that his words are provoking him, Grimmjow goes on, declaring that Ichigo came to Hueco Mundo not to save Inoue, but to fight Hollows out of his instincts as a Shinigami. Ichigo and Grimmjow once again clash blades multiple times in midair, culminating in Grimmjow launching a Cero. Ichigo disperses the attack with Getsuga Tenshō, but part of the beam pushes through, which he narrowly dodges.
However, Grimmjow uses this chance to flank him with Sonído again, managing to cut him across the chest. Landing on the ground, Grimmjow plants his sword into the ground. Dissatisfied with Ichigo's performance, Grimmjow slits his index finger with his blade, and proceeds to charge a Gran Rey Cero, hoping that it would provoke him into using his full power. Ichigo, still in midair, realizes that Inoue and Nel Tu are in the range of the attack. He yells at Grimmjow to stop, but he launches it anyway. The massive Cero inflicts an immense amount of damage to the surrounding structures; however, Ichigo manages to protect Inoue and Nel by donning his Hollow mask and getting in the way of the attack.
Surprised that Ichigo was able to save her, Orihime calls out his name. When Ichigo turns his head to look at her however, she is terrified by the sight of his Hollow mask. Realizing this, Ichigo tells her to be at ease, and that he would end the battle as soon as possible. Overjoyed that Ichigo had finally called forth his Hollow powers, Grimmjow begins to laugh manically, saying that it was the moment he had been waiting for. Grimmjow proceeds to release his Zanpakutō, throwing up a massive amount of sand as his spiritual power is unleashed. Looking on, Ichigo tells Inoue to shield herself and Nel with Santen Kesshun, and not to lower it for a moment. As the sand and smoke finally settles, Grimmjow's Resurrección, Pantera, is revealed. Grimmjow lets out a massive roar, which surprises Ichigo with its immense sound pressure. He then leaps towards Ichigo, catching him off guard, and strikes him with his arms, launching him through two massive pillars. While Ichigo is still hurtling through the air, Grimmjow intercepts him with Sonído and sends him into the sky with a knee strike. He intercepts Ichigo once more, knocking him down through a pillar, causing it collapse. Grimmjow looks down at the smoking rubble, remarking that this could not be all that Ichigo was capable of. Immediately, Ichigo appears behind him with Shunpo, and hits him with a Getsuga Tenshō. However, the attack leaves Grimmjow unharmed, who remarks that the look in Ichigo's eyes make him angry.
As the two continue to clash, Grimmjow overpowers Ichigo and slams him into a pillar. He remarks that Ichigo has somehow extended the amount of time that he can use his mask, and speculates that he either trained, or that he had somehow gotten stronger during their fight. Not caring either way, Grimmjow determines that if Ichigo's mask breaks, then the fight would become very boring; he proceeds to thrust his claw towards the mask. Before the blow could connect, Ichigo catches his hand, and slashes him across the chest, remarking that the fight will also get boring if Grimmjow doesn't remain in his released state. In retaliation, Grimmjow launches several punches and kicks at Ichigo, who manages to dodge all of them. However, he manages to strike him over the head with a lash of his tail, launching him to the ground once more. Grimmjow dives down to give pursuit, but Ichigo catches him off guard, cutting him across his left arm.
As he lands on the ground, he manages to block Ichigo's next attack. Pointing his elbow at Ichigo, Grimmjow launches five dart-like projectiles at him. Ichigo manages to dodge them, but realizes that they are heading straight for Orihime. He then intercepts all five darts, allowing them all to hit his back. After looking at Orihime once more, who recoils in fear of his masked appearance, he heads back into battle.
As Ichigo returns to Grimmjow, the latter remarks that Ichigo indeed came to save Orihime. However, he points out that Ichigo is taking on a lot of damage because of it, noticing his heavier breathing. To demonstrate the power of the darts Ichigo had allowed to hit him, Grimmjow launches one at a pillar behind him, completely demolishing it. He expresses surprise that Ichigo was still in one piece after getting hit by five of them. Noticing a crack on Ichigo's mask, he then asks if it is reaching its limit. Playing it off, Ichigo removes the crack, causing Grimmjow to remark on how stubborn he is. Ichigo points out that Grimmjow also appears to be damaged, but he denies this and attacks Ichigo, resulting in a clash that throws up a large amount of sand. As the two continue to trade blows, they each land a blow on the other's face, breaking off parts of Ichigo's mask and scratching Grimmjow's cheek. Grimmjow then lands a kick on the side of Ichigo's head, knocking him to the ground. As Ichigo recovers from the attack, Grimmjow comes spinning towards him, striking him and demolishing a nearby pillar. Grimmjow hits Ichigo with several successive blows, breaking off more and more pieces of his mask. He then knocks him against a pillar, having almost completely destroyed his mask. Grimmjow remarks that Ichigo has reached his limit, and that the battle is over. However, from the top of the nearby pillar, Orihime shouts out to Ichigo, telling him not to die and not to get hurt any more than he already has.
Hearing this, he effortlessly stops Grimmjow's next attack, telling him that he isn't allowed to sustain any more damage. With Grimmjow wide open, Ichigo is able to slash him right down the chest. Thinking that he has won the battle, Ichigo lowers his blade, but Grimmjow grabs onto it. Angry that Ichigo thought that such an attack could defeat him, Grimmjow stabs his abdomen with his claws, before pulling away. Grimmjow comments on Ichigo’s eyes again, remarking that regardless of many times he has hit him, they give the impression that Ichigo still thinks he can win. Enraged by this, Grimmjow attacks Ichigo once more. Ichigo blocks the first two attacks, mockingly asking if Grimmjow is angry because a mere Human is looking at him as if he were an equal. Grimmjow kicks Ichigo’s stomach, knocking him up into the air, and declares that regardless of whether somebody is a Human, Shinigami, or Arrancar, he will smash everybody who looks down at him into pieces. He then leaps towards Ichigo once more, only to suddenly appear behind him with Sonído. Grimmjow holds his wrists out together, with his claws extended, and tells Ichigo that he will start with him. With a slashing motion, Grimmjow then forms massive claws of spiritual energy on each of his fingers.
Ichigo manages to catch his footing in midair, and asks Grimmjow what the giant energy claws are. Grimmjow tells him that the ability is called Desgarrón, and that it is his strongest technique. He proceeds to swing one set of the claws at Ichigo, who barely manages to hold back their tips with Zangetsu. Despite this, Grimmjow manages to get past his guard, slashing him down the chest. He starts to laugh, shouting out that Ichigo will lose to him, and that he is the king. However, Ichigo again regains his footing, and pierces one of Grimmjow's massive energy claws with his blade, before completely shattering it with a single swing. Ichigo tells Grimmjow that he isn't the only who wants to win, and that he is his first target. Ichigo starts to fly right towards Grimmjow, who swings his other set of energy claws at him. In mid flight, he drags Zangetsu across one of the claws, tearing a path straight through it as he gets closer to Grimmjow. As he does so, he admits that he came to Hueco Mundo to fight and defeat Grimmjow, but that he also intends to defeat Ulquiorra and Aizen, as well as bring back Rukia, Chad, Ishida, Renji, and Orihime. Shouting that Grimmjow is just one person who cannot defeat him, Ichigo breaks through the rest of the energy claws and impales him with Zangetsu.
As Grimmjow starts to fall out of the sky, Ichigo catches him by the hand and leaves him on the ground, sparing his life. With the battle over, he returns to Orihime and Nel, who are glad to see that he is back to normal. He picks up Orihime, putting her on his shoulder, and carries her to the desert below. However, as he is about to take her and Nel with him to rescue Chad and Rukia, Grimmjow appears behind him. Severely weakened by his wounds, Grimmjow reverts to his sealed state, but is still determined not to lose against somebody like Ichigo. When Grimmjow attempts to slash at him with his Zanpakutō, Ichigo throws away Zangetsu and stops his hand, telling him that there is no enjoyment in fighting to the death if he has already lost. He tells him that he'll fight him as much as he wants, but that for the moment, he needs to stop. Stubborn, Grimmjow ignores Ichigo and attempts to attack him again, only to be suddenly struck from afar by Nnoitra Gilga's Zanpakutō. Nnoitra remarks that Grimmjow is a bad loser, and that it is his turn to fight the Shinigami. Critically wounded, Grimmjow weakly calls Nnoitra a bastard. Surprised that Grimmjow is still alive, he proceeds to finish him off, but Ichigo protects him, blocking his attack.