It wouldn't be too surprising if Sasuke is indeed stronger. Sasuke for most of it has been out on the road, on top-secret missions. He can't afford to be not-rusty, and this chapter confirmed it. It's not that he was rusty, it's that his dimension travelling ability takes a tremendous amount of chakra and he was temporarily unable to use some of his other abilities. Actually, in the fight, Sasuke had the upperhand until they targeted his Daughter which led him to getting somewhat injured.
Naruto on the other hand is now Hokage. While he's obviously been fighting now and again, he simply doesn't have the time to keep his skills fresh, even with Shadow Clones. He has a lot of responsibility right now.