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.
I think even though this happened a few years ago but this cannot be used as a reference because indeed they are now in a different phase and Chelsea may be more difficult now because their internal problems have not been resolved properly until now.
Madrid, on the other hand, are underdogs but after beating PSG in the previous round they look promising now