"A Clash of Fate: You Can't Bring Me Down!" (因縁の対決!オマエにオレは倒せねえ, Innen no Taiketsu! Omae ni Ore wa Taosenee) is episode 147 of the original Naruto anime.
Mizuki is determined to make Naruto and Iruka suffer, and it appears like he has the upper edge with his improved strength and speed. Meanwhile, Ino, Chōji, and Shikamaru are at their limits, and now Fūjin and Raijin are free. That is until Tsunade shows up and defeats them both easily. Fūjin and Raijin surrender and agree to return peacefully to the institution. Mizuki, on the other hand, has converted all of his speed to power and prepares to finish Naruto off. But, Iruka thinks up a plan and traps Mizuki, giving Naruto the chance to use the Rasengan on him. Mizuki reverts to his original form, badly damaged when Tsunade shows up and explains everything about the potion Mizuki took. Mizuki will no longer be able to fight as a shinobi. Iruka offers to treat everyone at the ramen bar, and thinks about how Naruto saved his life the same way he had saved Naruto before.