Everyone would expect Real Madrid to win this match in the end, but I think it's always possible to get Atletico Madrid to win it.
Real Madrid are quality team but it is always possible to expect them not to win one or more important matches. The probability of victory was high, but that would only depend on how well the player performed in the match. Consider Atletico Madrid to win, but that has a low probability.
There is only 1 ticket to the semifinals, both teams will desperately win it. Don't underestimate Ateltico Madrid even though this match was played at the Santiago Bernabéu Stadium. For other matches, Valencia and Bilbao were still tied at 0-0. Bilbao is likely to be expected to be success for 1 ticket, but Valencia is also possibility.
Morata put Atlеtico ahead, in the old days I would say that Real could be in trouble if Atlеtico had the same good defense as they used to. But now we can wait a bit and bet Real +1, or Real will score. It will be necessary to look at which event will have better odds. Atletico took the lead a little unexpectedly, but Real Madrid has been missing a lot lately, I think that Real Madrid wont give up so easily, all the struggle is still ahead.