The game hasn't even been released yet. We saw the Star Destroyer crash in a promo trailer, not an in-game cutscene, so it's hardly a valid or - at this point - a remotely canon-supported argument. This can wait until TUF comes out and we can see for ourselves what he's capable of.
In any case, Skywalker probably pulls the moon out of his ass and drops it on the apprentice's head. NJO sucks.