I'm not a Sasuke hater. I actually think he makes quite an awesome character. But I think that Pain would beat him. For one, for Sasuke to put Pein under Genjutsu, you'd have to do it to all SIX bodies. Tsukiyomi uses a lot of chakra, so it wouldn't be super easy to just yank out six Tsukiyomis in a day. Amaterasu also uses a lot of chakra, plus you'd have to hit all 6 bodies. If Sasuke used Amaterasu and Pein used Shinra Tensei, Shinra Tensei would not only block Amaterasu for a short while but it would hit Sasuke which would knock his focal point off. Not to mention all the Mangekyo techniques Sasuke would have to dish out, which would actually make him BLINDER as the battle goes on. I believe Sasuke is about to receive some kind of massive power up though...he always does. THEN he will be stronger then Pain.