"The Last Leg: A Final Act of Desperation" (届くかイダテ!執念のラストスパート!!, Todoku ka Idate! Shūnen no Rasuto Supāto!!) is episode 106 of the original Naruto anime.
Sasuke attacks Aoi with his Chidori, only to fail. Aoi sees his Sharingan up close and realises that he is a member of the Uchiha Clan, and remarks how the last of the clan is nothing but a failure who cannot live up to the family name and their Kekkei Genkai. Infuriated at Aoi's words, Sasuke attempts to kill Aoi with his Chidori again, but only manages to cause a crack in Aoi's Sword of the Thunder God. Aoi then throws Sasuke off a bridge, with Sakura following him in order to save his life. With Sakura and Sasuke out of the fight, it is up to Naruto to defeat him so that Idate can continue the race. Naruto attempts to hit Aoi with his Rasengan, only to fail as Aoi's sword is able to go through chakra. After attempting another Rasengan and using the Multiple Shadow Clone Technique to attack, Naruto notices the crack Sasuke had caused. Creating more shadow clones to distract Aoi, Naruto goes airbone and aims for the crack. hitting it with the Rasengan. The tactic works, and Aoi's sword is broken; Aoi himself is sent into the air and then down the cliff. With Aoi defeated, Naruto helps Idate catch up to Fukusuke.
Though Fukusuke is already near the finish line, with determination and encouragement from Naruto, Idate manages to catch up and win the race, seemingly saving the Wasabi family in the nick of time. However, the daimyō's minister objects, claiming that Idate cheated, as Naruto carried him for part of the race. According to the minister, this violates the rule that the runners must do the race on their own two legs. Just as it seems that Idate will be disqualified and the Wasabi family will be disbanded forever, the daimyō objects, declaring that no such rule exists. He then reveals a photo of the minister taking a bribe from the Wagarashi family, explaining why he had invented the rule. As a result of this, as well as other poor conduct, the Wagarashi are forcibly disbanded for all time.
As Idate's win has completed their mission, it is time for Team 7 to return to Konoha. Ibiki Morino arrives on a ship to transport them and the wounded Sasuke back to the village. Idate calls out to his brother, but Ibiki ignores him, stating that he has no brother anymore. Idate thinks to himself that he is now worthy of his brother, as he finally understands the 10th question, while Ibiki privately muses to himself how Idate has finally grown, crediting his growth to Naruto. Meanwhile, Sasuke is fuming on the ship, as he was unable to defeat Aoi despite using Chidori twice, while Naruto managed to kill Aoi.