However, he admits they were fortunate to avoid a late penalty call for Real attacker Vinicius Jr.
Perez said, "The feeling is positive and I am happy, satisfied and proud of this team. We have to improve because against important teams, and also against other normal teams in our League, maintaining the lead is key to being able to get more points in the standings.
"The feeling is good but we must improve because we conceded goals that should not be repeated. Today, when we were 2-0 up, we stopped being vertical in pressing, something we trained for, because we are not used to running more slowly across the field. We misinterpreted it."
"You can't go all out against any team, and even less against Real Madrid, and lose your head in moments like that. We had to stay calm, pass the ball around and have orderly situations. This team, if you lose the ball in an inappropriate situation, makes you pay for it. Today we have to appreciate that with 2-3 we were able to equalise."
Perez was also asked about the controversial play that occurred in the final minutes with a kick from Mumin on Vinicius inside the area - which the referee did not consider to be a penalty.
"I don't like to lie and I think it was Abdul Mumin who kicked him. I always try to be honest and when I saw it I said that he could whistle it but also not. These are delicate plays and you have to be extremely careful with the VAR," he added.