Madrid trail 2-1 from the first leg but Mourinho feels his players' composure bodes well as he looks to set up a possible showdown in the final against his former club Chelsea.
He said: "I don't know if the Champions League is more important than the league, because the best team always wins the league and this isn't always the case in Europe.
"However, the final of the Champions League is the most important thing in football. Today is almost like a long-awaited final, but I see calmness in the players. I don't like an excess of emotion, nor a lack of it."
Mourinho claimed he had been bereft of fortune in previous matches at the last-four stage after twice losing to Liverpool (in 2005 and 2007) - when at Chelsea - and again to arch-rivals Barcelona last season - a defeat he blamed on a UEFA conspiracy.
"Overall I have not been lucky in semi-finals of the Champions League," he said.
"I lost one with Chelsea (2005) due to a goal that wasn't a goal, the ball didn't cross the line. Another season (2007) we lost on penalties and when you lose a semi-final on penalties it is due to bad luck and I lost the semi-final last season because of what everyone knows."
Bayern Munich coach Jupp Heynckes is preparing for a "battle of the giants".
He said: "It is going to be spectacular. It is going to be a real treat with everything which belongs in such a football game.
"Just a fortnight ago, people were saying that Barcelona are the be all and end all, but now Real have gone and won in Barcelona.
"It will be a battle of the giants. Both clubs have a great history and I am looking forward to it, and I hope it has a positive outcome for us."