I think Hughes might have gassed himself in the first inning, which isn’t uncommon for a young starting pitcher. He was really throwing his FB well in the first, touching 95 when he was in trouble. But it hasn’t been the same in the last couple innings, and that could probably be traced back to the first.
It’s probably much easier to pace yourself in a regular season game, when there’s much less on the line. But once Hughes got in trouble in the first, he really seemed to let it loose, and it may have been what cost him here.