Real Madrid must raise their game ahead of the Champions League's last 16 after their LaLiga title hopes took a "heavy blow" against Real Betis on Saturday.

That is the view of Carlo Ancelotti, who oversaw a 2-1 defeat at the Estadio Benito Villamarin, as former Madrid midfielder Isco scored the winner from the penalty spot.

Madrid missed a chance to go top of LaLiga, remaining level on 54 points with Barcelona, with both teams two adrift of Atletico Madrid after Diego Simeone's side beat Athletic Bilbao elsewhere on Saturday.

Madrid face their neighbours in the last 16 of Europe's premier club competition on Tuesday, and Ancelotti has warned a similar performance will ensure that first leg does not end well.

"This is a heavy blow, we have to bounce back. Losing at this point in the season is tough because everyone is on form and we didn't do well in this game," the Italian said.

"We lost 27 balls in the first half and Betis got back into the game. If we play like this, we certainly won't win on Tuesday.

"I hope this serves as a wake-up call. It seemed that lately we were more organised, more compact, and today we weren't able to do it like in the previous games."

Ancelotti explained his decision to bring on Endrick for the team's top scorer Kylian Mbappe in the closing stages of the game, saying the France forward had been unable to fully train due to a dental issue.

"Mbappe had a problem this week and didn't train much and wasn't at his best level," he said.

"To avoid problems, I took him off and put Endrick on, who has been in good form."

Madrid host Rayo Vallecano in LaLiga next Sunday after their Champions League clash with Atletico, who could lose top spot in the table to Barcelona on Sunday.