Cristiano Ronaldo is convinced Real Madrid will regain the Spanish league title from Atletico Madrid, despite the 4-0 loss at their rivals.
Real suffered their heaviest defeat in more than four years but still lead La Liga ahead of Barcelona and Atletico.
Barca are a point adrift, with Atletico four points back in third.
"In my opinion we are a better team than Atletico and we should be showing that on the pitch. I'm sure, in the end, we'll win La Liga," Ronaldo said.
European champions Real are aiming for their first La Liga in three seasons and took control after a 12-match winning streak in the first half of the season.
But their four-point advantage over Barcelona was reduced at the weekend as Atletico's win, coupled with the Catalan club's 5-2 success at Athletic Bilbao, reignited the title race.
"It was a day to forget but we are still top of the league and we know we'll have to fight right until the end," Portugal captain Ronaldo added.
"We have to put this game behind us as quickly as possible because Real Madrid can't lose 4-0 to any team."
Meanwhile, Ronaldo's agent Jorge Mendes has defended the player for hosting his 30th birthday party shortly after the loss.
The Ballon d'Or winner was seen enjoying the celebrations in a video leaked to the Spanish media.
"Ronaldo was devastated after the defeat and people spent two hours trying to cheer him up," Mendes told Spanish radio station Cadena Ser.
"The fact is that his birthday party had been organised more than a month ago and he had family coming from abroad.
"He didn't want to cancel out of respect for the people that came. What is inadmissible is that somebody takes advantage of a private affair to release a video."
Spanish football expert Andy West says Real's fans are not happy - especially with Ronaldo
"Real Madrid's players have bridges to build after their feeble derby day capitulation against Atletico - and none more so than Cristiano Ronaldo.
Even more than the margin of defeat, fans are furious at the nature of their team's performance, which lacked any kind of fighting spirit.
That impression of indifference was only strengthened by the sight of Ronaldo dancing the night away at his 30th birthday party within a few hours of the final whistle.
The excitable Spanish media have interpreted Ronaldo's festivities as a sign of aloof arrogance, and Real's players will be under huge pressure to visibly demonstrate their commitment when they next appear in front of their fans against Deportivo La Coruna on Saturday."
|Atletico's recent run versus Real|
|Atletico 4-0 Real||7 February, 2015||Vicente Calderon||La Liga|
|Real 2-2 Atletico||15 January, 2015||Santiago Bernabeu||Copa del Rey|
|Atletico 2-0 Real||7 January, 2015||Vicente Calderon||Copa del Rey|
|Real 1-2 Atletico||13 September, 2014||Santiago Bernabeu||La Liga|
|Atletico 1-0 Real||22 August, 2014||Vicente Calderon||Spanish Super Cup|
|Real 1-1 Atletico||19 August, 2014||Santiago Bernabeu||Spanish Super Cup|
|Real 4-1 Atletico (aet)||24 May, 2014||Estadio da Luz, Lisbon||Champions League final|