Luke's body started to disintegrate as the Titan Lord began to return to his true form, but Percy gave Luke Annabeth's knife, which he used to stab himself in his weak spot, defeating him, and reducing Kronos to dust though not killed.

How does Percy beat Kronos?

In The Battle of the Labyrinth, Percy and his friends enter the Labyrinth to stop Kronos's army from invading Camp Half-Blood. ... Luke overcomes the force of Kronos within him and stabs his own mortal spot, which defeats Kronos and saves Mount Olympus.

Who defeated Kronos?

When Zeus was born, however, Rhea hid him in Crete and tricked Cronus into swallowing a stone instead. Zeus grew up, forced Cronus to disgorge his brothers and sisters, waged war on Cronus, and was victorious.