Natsu just wrecked one of the Spriggan 10, and he probably isn't even fully awakened yet. It might take a bit for him to get to full power, but even if he's not, Dimaria said that his power was like that of the gods, and she probably didn't get a glimpse of his full strength.I'll laugh if the opposite happens.
Not to mention that the guy Gray beat said that Natsu needed to die because Zeref was the one who needed to beat Acnologia, but Natsu was a threat to that, which implies that Natsu has power comparable to both Zeref and Acnologia.