Matchwinner Carlos Romero struck late after avoiding a red card for a heavy challenge on Real striker Kylian Mbappe.
Afterwards, former Real midfielder Alvaro Benito said: "Sometimes it's not enough to speed up the last 30 minutes when you find yourself up to your neck in water.
"You have to go out with the right determination for each game. Madrid is lacking a consistency in performance that generates optimism. You can always be optimistic about Madrid because of the talent they have, but I don't see the plan being consistent in many games. Today it came up tails, the opponent got one right and you're left without points."
Meanwhile, AS's editor and Real fan Tomas Roncero also stated: Madrid didn't realise until the 70th minute that they had to go all out in the match. And the refereeing errors were decisive in the final result. Not only in Carlos Romero's goal, who should have been sent off. I still don't see Vinicius' goal being disallowed. He didn't intervene in the tussle between Pol Lozano and Mbappé."