Amaterasu!

is episode 137 of the Naruto: Shippuden anime.

Synopsis
As Itachi moves in to take his remaining eye, Sasuke manages to overcome the Tsukuyomi he was placed under. Returning to normal, the brothers switch from genjutsu to ninjutsu, and exchange fire jutsu, with Sasuke gaining the upperhand. In the struggle, Itachi activates Amaterasu, which seems to severely injure Sasuke. However, Sasuke had used Orochimaru's substitution jutsu to escape the flames. Itachi gloats, claiming Sasuke has no chakra left, but Sasuke reveals that he had come prepared, and had one last technique left that would make his dream of killing his brother a reality.