Real Madrid coach Carlo Ancelotti defended his players after defeat at Atletico Madrid.
Yannick Carrasco struck from the spot for the only goal of the game.
On 40 minutes, Matheus Cunha drove through the middle and was bundled down in the box by Jesus Vallejo. The referee initially waved play on, to the displeasure of the raucous home support at the Wanda Metropolitano, but a delayed VAR check gave them what they wanted.
Ancelotti later said: "Now is not the time to criticise at this stage. We weren't pleased with the first-half performance because we misplaced a lot of passes. The mental part of the game is very important in matches like this.
"At times, it's crucial. Atlético had an edge in this respect. We didn't need the points, but we needed to put in a good performance. We did better in the second half. We needed to rest the tired players to prevent any potential problems.
"It was a good game, particularly the second half. We were close to drawing the game and we have to carry that forward. Our priority was to avoid any problems and for those players who haven't played as much, to get some minutes. It'll be like that in the next matches. Those who played the least today will play on Thursday. Benzema, Modrić, Vinicius... These games help us to find our rhythm and we had that until the end today."