Ronald Koeman was furious with the referee for not awarding Barcelona a penalty in their 2-1 defeat to Real Madrid.
The Catalan Giants missed out on the chance to go top after goals from Karim Benzema and Toni Kroos helped Los Blancos to a 2-1 win, with Oscar Mingueza's second half effort not enough to inspire a comeback despite Casemiro's late sending off.
At the final whistle, Koeman appeared to rage at the referee after his side had two late penalty claims refused as Martin Braithwaite twice went to ground in the box under challenges from Ferland Mendy.
Damsgaard price set as Liverpool, Spurs, Barcelona and Juventus consider swoop - Paper Round
- Benzema and Kroos give Real Madrid title hope after crucial El Clasico win
- Is El Clasico dying? The bang has gone from football's greatest firework
And in his post-match interview, the boss was still aggrieved that his side were denied a chance to complete the comeback.
"If you're a Barcelona fan and you saw this game you'd be very annoyed with two of the referee's decisions. It was a clear, clear penalty and then he only gave four minutes of stoppage time," the Dutch coach told Spanish network Movistar.
It is Barcelona's second defeat to Real Madrid this season, the last a 3-1 defeat where Koeman also claimed his side were the victim of some poor refereeing decisions.
"Once again we just have to accept it and shut up," he added. "All I ask is that the referee makes the right decisions."
With all three points secured, it was Real Madrid who went atop the table instead by leapfrogging Atletico Madrid, who have a game in hand.
The three-way La Liga title race is shaping up to be a thriller, and Real boss Zinedine Zidane insisted his side were top on merit rather than off the back of lucky decisions.
"We should be very happy with our performance and you cannot say it was all down to the referee, we deserved the win," he said.
"If the referee says it wasn't a penalty it's because it wasn't one. The important thing from our point of view is what we did on the pitch. We made an excellent start then suffered a bit because Barca are a great side but we had a lot of chances to score the third goal. In the end the win was well deserved.
'Dream' - Barca players 'desperate' for Neymar return - Euro Papers
Barcelona struggle to ditch Griezmann - Paper Round
'I'm moved' - Benzema sends message to France fans after early Euro 2020 exit