While acknowledging Dortmund's superiority, the outspoken Portuguese manager was clearly vexed at seeing BVB's attacking star hit four times against an under-par defence
The Poland international hit all of his side's goals in a dominant 4-1 victory at Signal Iduna Park, becoming the first man to reach such a tally in a single semi-final match during either the European Cup or Champions League eras. The win leaves Dortmund on the verge of reaching the final, although Madrid will have the chance for revenge next week on home soil.
Speaking after the match, the Portuguese trainer was irritated with his backline, slamming them for failing to control Lewandowski even though they knew what to expect from the striker.
"We know everything about Lewandowski, absolutely everything, we studied him from every detail possible and we lose him in three goals - i don't talk about the penalty - where we know exactly what he does," Mourinho explained in the post-match press conference.
"It's of course very disappointing. When I lose and I don't deserve to lose, for me it's a drama, when I lose and I deserve to lose, it's a situation I don't accept."
While careful not to take away merit from Dortmund, whom he said were the best team, Mourinho was frank as he described his side's failings on what was the biggest game of their season so far.
"We prepared the game as well as we do always but also in the semi-finals we were ready for everything, we were very confident about the work we did," he added.
"I think many of the boys did not have a good night, and this is exactly when you can't make mistakes because at club level this is the second most important night in the world of football.
"German football is, of course, top football, and in this moment is having a generation with very good players. But I think Spanish football is Spanish football. It has probably the two biggest teams in the world and I think you cannot judge by a moment.
"But the reality is in this match - and I don't speak about [Bayern Munich against Barcelona] - in this match the best team won.
"We still have hope. I think that if you speak with the players now they will say there is none, but in 30 minutes time they will start to say yes, and in a day's time they will say yes again. On Tuesday all of them are going to be ready to play with everything.
"My message is this: in football, everything is possible. And in the same time, you cannot be out of the competition without trying on the pitch. And if Borussia eliminate us, I hope they will do it feeling they have suffered, with the players having tried their hardest."
Mourinho and Madrid will attempt to make amends for the defeat when they host Dortmund in the Santiago Bernabeu on Tuesday needing at least three goals.