Meanwhile, this is a result of their preparation for the Champion League after defeat in their first Champion league appearance in the year 2010–11.
It is obvious that Real is still not playing at the top level and has certain problems in the game which does not diminish the size of the Sheriff's victory.
Sheriff has been playing in European competitions for a long time, as far as I remember they also played in European League groups and their success is not accidental but is the result of long and hard work and investment.
This is a signpost for other, small clubs, how to achieve a good result in European competitions.
^^ I won't say that Sheriff's win against Real is totally luck. Yes a bit of luck was there, but they really did play well if you watch the match. They got so much less opportunity to score compared to Real Madrid but they converted each chance they got. Having a 100% conversion rate against Real is always something huge. Also, Real Madrid is having some defensive problems since Ramos and Varane left. But we cannot deny that Sheriff had a great match and they deserved the win.