The Secret Weapon is Called…

is episode 15 of the Naruto: Shippūden anime.

Synopsis
After the visions that Itachi makes him suffer, Naruto is released from the genjutsu by Chiyo and Sakura. Distracted and immobilised by Kakashi's shadow clone, Itachi takes a direct hit from Naruto's Big Ball Rasengan. Meanwhile, Neji frees himself, Rock Lee, and Tenten after Guy defeats Kisame. Later, the two Konoha teams find, to their surprise, that the two foes that they had defeated are neither Itachi nor Kisame, but two entirely different people, who the Akatsuki leader had used to stall the Konoha teams using Itachi and Kisame's likenesses.