An angry Ronald Koeman criticised referee Gil Manzano after his Barcelona side were beaten 2-1 by rivals Real Madrid in a match which could have a huge bearing on LaLiga's title race.
Madrid moved to the top of the table as first-half goals from Karim Benzema and Toni Kroos proved decisive at a rain-sodden Alfredo Di Stefano Stadium, with an Oscar Mingueza strike on the hour proving to be Barca's only reward for bossing possession.
But Koeman – who walked out of one television interview after the match – was furious that substitute Martin Braithwaite was not awarded a late penalty after tangling with Ferland Mendy inside the final 10 minutes.
After the final whistle, Koeman confronted Manzano – a late replacement for the injured Mateu Lahoz – on the pitch.
"If you are from Barcelona, you are very, very unhappy about two decisions from the referee," Koeman said in comments reported by Marca.
"First, I want to say we did not play well in the first half, neither in defending or attacking. In the second half we improved.
"I only ask that the officials get things right. It's a penalty. And then they add four minutes, when they have stopped the game for more... the penalty is very clear.
"I don't know why we have VAR in Spain. Everyone has seen the incident... the way Martin falls, it has to be a foul. The referee may not see the play, but we have VAR for situations like this. It is better not to say more."
Koeman said his players – who had surrounded Manzano at the time of the incident – shared his anger over the decision but insisted defeat did not need to be a fatal blow for their title hopes.
"I am optimistic," he said. "We have shown that we fight. We are going to react and fight until the last game."
Zinedine Zidane called it "a deserved victory" for his side, dismissing Koeman's complaints.
"I believe the referee did not whistle for a penalty because it is not a penalty," he said. "But we suffered because Barcelona are a great team."
The result leaves only one point separating Real, Atletico and Barca at the top of the table, at least until Los Rojiblancos face Real Betis on Sunday.
Though the importance of this result will not be lost on Zidane, the manager cautioned that much could still change in the title race given the hectic schedule.
Lucas Vazquez was replaced late in the first half and will now be an injury concern for the second leg of their Champions League quarter-final against Liverpool on Wednesday.
"Nothing changes," Zidane said when asked about the league table. "There is a long way to go. We have to rest for now. It has been two hard-fought games. Now we have to rest. I don't know how we are going to end the season. Physically, we are at the limit."