Chelsea quality in the Premier League in the last few matches has been very entertaining, but Chelsea must be careful when dealing with Real Madrid in the Champions League. Real Madrid will be very dangerous when they have the ball. Real Madrid will turn into a savage wolf who can kill the opponent's game because they have a lot of quality. They have proven when dealing with PSG and facing Real Madrid is a tough job for Thomas Tuchel.
The probability of Chelsea winning against Real Madrid in my opinion is much better in the first leg. Chelsea are playing at home and that should be the reason why they will be favorites to win over Real Madrid.
I don't think Real Madrid are far superior to Chelsea this season. Real Madrid's defense is not good, their midfield is not as good as a few seasons ago and they only rely on Benzema as a goalscorer. You will probably know that there will be a tight guard for Benzema in that match if he is really available, and that man-marking strategy will get Real Madrid in trouble.
Champions League 2020/2021 season Chelsea managed to beat Real Madrid 2-0 at Stamford Bridge so that Chelsea managed to qualify because at the Santiago Bernabeu they got a 1-1 draw based on head to head in the UCL. This season will look different and it is still difficult to predict who will advance to the semifinals. Even so, I believe Real Madrid will qualify. Chelsea's chance to qualify is still there by not letting Real Madrid dominate possession.