The Italian suffered his first reverse against the Catalans since returning to Madrid last summer
Carlo Ancelotti could not hide his disappointment as he watched his Real Madrid side crumble to an emphatic 4-0 Clasico defeat at the hands of Barcelona.
The visitors ran out convincing winners at the Santiago Bernabeu, having dominated the game almost from start to finish.
Madrid were without star striker Karim Benzema but Ancelotti was in no mood to make excuses after a performance for which he took full responsibility.
“It is tough because it is a Clasico, for the fans when we play against Barca… it is a blow, we have lost a battle, we still have an advantage and we have to stay calm and get back our injured players,” Ancelotti explained to reporters after the game.
“We were unrecognisable, everything went wrong, we have to forget that and move forward, we have a big lead [in La Liga]. I, the coach, am at fault.”
Despite Sundays humiliation, Madrid remain in pole position to wrest the Liga title back from neighbours Atletico at the end of the season.
The leaders sit nine points clear of Sevilla at the top, with Barca three points further back, albeit having played a game fewer than their rivals.
Ancelottis charges will now have two weeks to regroup due to the international break before returning to action on April 2 away to Celta.
Four days later they travel to Stamford Bridge to face Champions League holders Chelsea in the first leg of the clubs quarter-final tie.