Jose Mourinho said Real Madrid could not afford to lose to Barcelona after their victory at Camp Nou cut the leaders’ advantage from six points to three.
The result moved Real Madrid back into contention at the top of the table, while a defeat would have left them nine points behind their Catalan rivals.
Mourinho said that margin would have placed his side under serious pressure as the season continued.
Real Madrid’s next match is on 1 November, when they travel to face Racing.