If you don't believe me check the Kakazu and Hidan arc. The Invasion of Pain proves it, he lost to two Paths of Pain (barely held up against just one) while SM Naruto fought five at once.
This again?
1. It was Kakashi who obtained intel about Pain without which Naruto wouldn't have won.
2. Kakashi fought two paths, yes. One of which was the strongest of Pain's bodies.
3. You DO realize that Naruto didn't face Pain at his full stamina like Kakashi and the rest of Konoha had to?
4. And you DO realize that for the half of Naruto's fight Deva's abilities were restricted due to the use of large Shinra Tensei on the village?
5. And you
DO realize that Naruto would have lost against Pain anyway, if it wasn't for Hinata awakening the Kyuubi?
6. Finally, you DO realize that Naruto had prep time, unlike anyone in Konoha?
That "one path Kakashi barely held up against" was the one that 6-tailed Naruto couldn't defeat. The only difference is, against Naruto, he was already exhausted.