Celtic lost at home to Juventus. They lost 3-0. They deserved to.
Unfortunately, fitba (I somehow typed "football" as "fiitl" so it must be what my subconscious was going for) doesn't work based on how loudly fans sing, how exciting the attacking play is, how far and fast a defender travels after playing in an international tournament abroad and, most pertinently, how many penalties you should have been awarded. It works based on how many times you put the ball in the back of the net and how many times your opponents do.
Celtic largely did ok with Andrea Pirlo. He was the dangerman and Scott Brown gave him grief, though the Italian made him look a mug on a couple of occasions. But Juve, as the best side in Italy, have several excellent players and their clinicalness in front of goal bore this out.