Strength of Uchiha
Sasuke begins to attack Naruto, but Sai restrains him only for them both to be blown away by Sasuke's Chidori Nagashi. Sakura charges at Sasuke, but Yamato intervenes and winds up being stabbed by Sasuke's unique blade infused with his Chidori. The Nine-Tailed Fox tempts Naruto with its power, but he refuses it. Sasuke sees this using his Sharingan, appearing in Naruto's mind. The Nine-Tails says that Sasuke's chakra reminds him of Madara Uchiha, then Sasuke suppresses the Nine-Tailed Fox's chakra. Before the Nine-Tailed Fox returns to its cage, it warns Sasuke not to kill Naruto, saying that he will live to regret it forever.
Aired 20/03/2008EP 52 - Strength of Uchiha
Naruto: Shippuden
Naruto: Shippuuden is the continuation of the original animated TV series Naruto. The story revolves around an older and slightly more matured Uzumaki Naruto and his quest to save his friend Uchiha Sasuke from the grips of the snake-like Shinobi, Orochimaru. After 2 and a half years Naruto finally returns to his village of Konoha, and sets about putting his ambitions to work, though it will not be easy, as he has amassed a few (more dangerous) enemies, in the likes of the shinobi organization; Akatsuki.
(Source: Anime News Network)