Naruto didn't have time to stop he had one more thing to do he ran towards where Kakashi and Zabuza was fighting.
Kakashi had already summoned his ninken dogs and was powering up a Chidori and running towards Zabuza.
With Haku not here to save him Naruto knew that he should himself. Because if he didn't the effort of saving haku would've gone to waste.
As he probably would kill himself out of guilt knowing that Zabuza died because he wasn't there to save him.
Naruto made a clone and threw threw it with all his might as he flopped down from exhaustion.
The clone flew at astonishing speed as it headbutted into Kakashi's back causing him to trip forwards instead of hitting 'Zabuza's heart it cut his right arm completely off.
As the dogs dispelled and naruto used the substitution to switch himself with his clone as it DE spawned and went back to the lobby