PSG is huge force now without any doubts, but how Real played in defence yesterday was disgraceful. Like that Rudiger mistake - in lower level leagues very likely that he would accussed for match fixing after such mistake.
Don't expect that Chelsea can beat PSG, but I think that they will give more fight than Real. Or I just want to think.
Looking at how often Chelsea also make defensive blunders, especially with the combination of Robert Sanchez in goal, the game might even end before it gets started.
Chelsea would have to make close to zero defensive errors for them to stand a chance of staying in the game long a enough to steal a win, because they'll definitely not be able to win the game if PSG does draw first blood.