Guadalajara beat Barcalona 3-1 last year.

So yeah BS like that happens, but it's all a matter of luck. I've beaten stronger teams with my half arse squad with my 2nd best midfielder injured and two defenders. even yesterday someone played me like 5 in the mourning (changed the time of the match so he'll only be spectating) and my team somehow pulled out a win even with my formation not set properly.

But hey it could be worse. *cough* FIFA 12 *cough*