I think EA call it "momentum" and it's definitely the worst thing about FIFA.
It happens so often in manager mode, that's why I don't bother playing against the CPU anymore. You can be crusing in a game, then the 80th minute comes and suddenly the other team starts pressing with so much intensity. Not only that but your players start taking ridiculously heavy touches and losing the ball so carelessly. And don't get me started on smaller players beating big centre backs in the air, seen the likes of Messi and Victor Moses tower over Sergio Ramos and score in injury time. Makes it feel like the game is conspiring to make you lose or at least make it interesting.
Small players beating monstrous CBs in the air have resulted in many a broken controllers.
I can handle the exceptional pressure from the CPU or opposition, that's whatever, what I can't handle is when the performance of my team turns to rubbish for no discernible reason at a certain stage in the game.
It got to a stage where I would just shut down, and refuse to play properly, as I would just pass the ball amongst my defense and GK.
If the game wants to **** with me, I can **** it right back.