Naruto would hand Saskue his ass on a nice silver platter. First off, the development stage has drastically changed since there training in the forest (when they were running up trees) Naruto has become more powerful while Saskue lingers.

Secondly look who's training Naruto. A Sannin. He can now pass on all the technique's he has learned from the Third. Saskue does have Kakashi, but he is no Sannin. Let's look at the technique's Naruto now has mastered because of Jiraiya. He can summon the Frog boss Gambunta, and has recently learned the Rasengan. IMO; the Rasengan is more powerful than the Chidori. Saskue has learned what ? The chidori and that's it from Kakashi. I think Kakashi will train Saskue on how to properly use the Sharingan now.

This is a no contest fight. Naruto wins easily.