You need to go read the chapter again then. Orochimaru's body started rejecting him and he was laying on the ground completely vulnerable. Yamato restrained Naruto at this point, but if he had not, Naruto could have easily killed Orochimaru. As for the part of the fight that matters, Naruto was absorbing all of Orochimaru's attacks while Orochimaru was having to dodge/defend or be killed. Now, how was Orochimaru wiping the floor with Naruto?