Real Madrid suffered a surprise 2-1 defeat at struggling Valencia on Wednesday as they missed the opportunity to extend their lead at the top of La Liga after losing for only the second time in the league this season.
Simone Zaza, who endured an unhappy loan spell at West Ham United earlier this season, gave Valencia the lead in the fifth minute with a brilliant shot on the turn and Fabian Orellana added the second in the ninth.
Cristiano Ronaldo headed Real back into contention just before halftime, but the visitors were unable to build on their momentum after the break.
Real remained top on 52 points, one ahead of Barcelona and three clear of Sevilla in third, and still have one game in hand on both of their title rivals.
"The truth is we lost the game in 10 minutes. We started well with the ball, we had chances but we made two errors and they scored two goals. We had 80 minutes to rescue the game and tried but we lacked many things today," Real coach Zinedine Zidane told reporters.
"We had the chance to pick up points and we didn't do it. I hope this has no psychological effect on us. We need to be more focused in future games because if you don't concentrate you get punished. In those 10 minutes we weren't clever or ready."
Real's match at Valencia was rearranged after the original fixture was postponed in December due to Zidane's side taking part in the FIFA Club World Cup.