Newcastle was destroyed

It's funny that before this game, Newcastle had won 3 games and scored more than 2 goals in each of the 3 goals. It was normal for them to score 3 or 4 goals and not concede a goal. They were games against weak teams. Today they played against a strong team and were destroyed. It seems like they can only beat weak teams. Fortunately for them, the next game will be against a weak team. They will score a lot of goals and will win.

How can I explain to someone that this same Newcastle trashed Crystal Palace 5-0, and Crystal palace trashed Aston Villa 4-1?. Football, especially the English premier league is full of drama. Big teams gets humbled by smaller teams when we don't see it coming. It was a five goal thriller, but I don't really know why Tielemans wasn't awarded the third goal. I understand that there was a deflection, but the goal seems fair to me.
As it stands, Newcastle needs to do everything in their power to make that top five. This is not the time to start dropping points. About five games left, so any team stands a chance of making it to the top.