Aspas scored from the spot to earn the point from Madrid, having been out injured for the previous six weeks.
He said, "I had a very good feeling. We had one more player and I knew we were going to have a lot of the ball in the opponent's half and I am very happy to be back playing and feeling important in the team.
"It was a roller coaster. The first few minutes, when they were down to one player, you thought we could get the win. No one had ever won at the Metropolitano, we had it in our hands. It wasn't to be and we will keep fighting.
"We had 2-3 very clear chances to make it 0-2, when you don't score in a stadium like the Metropolitano, they tied the game with a long ball in an unfortunate play. We still had a few more counterattacks to win. In any case, we are happy to get a point on a very difficult pitch."