The manager told Sky Sports News: "I think the game, until a certain minute it was very, very, very, very equal. The first half was more ours than theirs but finished with a 1-1 which was a completely open result. One minute in the second half decided everything. A minute where the Atletico goalkeeper makes an impossible save to a John Terry header then the penalty that kills the game.
"After that 2-1 against Atletico is almost impossible, after that there was only one team, a team with morale high. Obviously it is disappointing to lose a Champions League semi-final with a second leg at home, but I am proud of them. We never really had Atletico in a position where we had an advantage and they had to chase the game, we had that for 10 minutes and they equalised.
"I think until the penalty they were not the best team. We conceded a poor goal, we knew that in set pieces we had a chance, John Terry had a header and the save was amazing. After that there was only one team."
Atletico will face Real Madrid in next month's final in Lisbon.