Real Madrid coach Carlo Ancelotti was adamant that his side should have had a penalty as they went down 2-1 to bitter rivals Barcelona on Saturday afternoon.
Cristiano Ronaldo was brought down in the area by Javier Mascherano with 19 minutes left in the game at the Nou Camp, at which point Madrid were one goal down, after Neymar had given Barca the lead in the 18th minute.
Referee Alberto Undiano Mallenco waved play on after Ronaldo tumbled under the Argentinian's challenge, to the fury of Ancelotti and the Madrid substitutes.
Seven minutes later, Alexis Sanchez finished off the game by scoring a superb lob, although Jese grabbed a consolation goal for Madrid in stoppage time.
"Naturally the penalty was very clear for me. I think everyone saw it, the only person that didn't see it was the referee," Ancelotti said in the post-match press conference.
Madrid's players also thought they could have been awarded a spot-kick towards the end of the first half for a handball by Barca left-back Adriano.
The Brazilian had already been booked before the incident and, although Ancelotti was less certain about the handball, he reflected: "It's a difficult decision, but it was at an important moment and if the penalty had been given, it may have been another yellow card too."
Madrid captain Sergio Ramos, who was deployed in the unfamiliar position of central midfield, was more disparaging about Mallenco's decisions.
The defender told reporters: "The team fought toe to toe against a very difficult team, and by the end we had them on the ropes, it's rare that you see Barcelona trying to waste time at the end of a game.
"But there were two clear penalties and although I don't like to try and justify defeats by talking about referees, there are some things you cannot fight against."
Ancelotti explained that he played Ramos in midfield because Asier Illarramendi had a muscle strain following the 2-1 win over Juventus in the Champions League on Wednesday, and defended the decision to field the Spain international alongside Luka Modric and Sami Khedira in midfield, a cautious tactic despite promising before the match to take the game to Barca.
He said: "I played Ramos there to look for balance in the middle of the park, I asked him about it before and he said he wanted to play there, so I put him in."
He added: "I didn't play defensively, Modric isn't a defensive midfielder, and Marcelo, (Dani) Carvajal and Cristiano and (Angel) Di Maria are attackers. Barca did not play with any more attackers than we did."
Reflecting on what was his first experience of a Clascio, the Italian said: "It's a fantastic game and atmosphere. I think it was a good game, we showed we can play well against a fantastic team. Of course you want to win this kind of game but at the moment we are improving and this game proves that."
Barca boss Gerardo Martino refused to comment on the refereeing decisions, instead remarking that his side had started the game well but dropped off towards the end.
He also compared the team's performance as a whole with Lionel Messi's.
"We played well at first but tailed off, and the same is true of Messi," said the Argentinian coach.
"But he worked hard and I rate his performance. If he, and the other players, can continue playing this well, we're going to have a good season."
Barca moved six points clear of Madrid at the top of the Primera Division and four points above Atletico Madrid, who play Real Betis on Sunday.
But Martino was careful about saying what effect the result would have on the title race.
"The victory is good for our spirits, and is more important in that sense than mathematically," he said.
"There is still 60 per cent of the league season left, and Madrid and Atletico are close to us, they can still make up the difference."