Before he drank the water, or after? If before, Goku barely loses to full power sage-chakra mode Naruto, just because they can't use blasts(if they could, a single kamehameha wins this for Goku), but if after, Goku rofl-blitzes Naruto with twenty zanzouken counters and sends him to the moon with his power pole, where Naruto's head pops before he can do anything about it.
This Goku was strong enough to beat King Piccolo, who could easily defeat Roshi, who in turn could easily beat that Krillin, who could lift 20 ton boulders. I thought we were talking about the Goku who first trained with Korin to GET the water. The one who easily STOMPED Taopaipai, who threw a log nearly two thousand miles and jumped on that ***** and RODE a log that he threw, to travel, survived getting hit with a moon busting attack from Goku, and a grenade exploding in his face after he was already severely weakened.
The point is, if Goku can send dinosaurs flying without training, he can easily lift Kurama with his power pole, and send him and Naruto flying to the moon, which is then destroyed by Roshi...