Naruto lost the second Konoha got blown up. I am not saying he is losing the fight, but he already lost the battle.
I've got a feeling Pein has a trick for handling bijuu up his sleeve. Akatsuki has been collecting them for a few years now. He might have been defenseless against Naruto's Sage Mode, but if he has a plan for dealing with the Kyuubi, Pein has won. I don't think Naruto is going to win this fight, even with the Kyuubi's help.