The Spanish press did not hold back in their criticism of a "shattered" Real Madrid, a team "in crisis" after their 1-0 home defeat at the hands of Villarreal in La Liga.

"Inexplicable" was the front-page headline on Madrid sports daily Marca on Sunday, which remarked that the reigning Spanish and European champions "don't know what is happening to them" in La Liga.

Just days after Zinedine Zidane signed a new contract until 2020, serious questions are being asked of the Frenchman's ability to turn things around after two trophy-laden years in charge.

Real have picked up just one point from their last three league games and have won only once in five, form that leaves them fourth in the table, 16 points behind leaders Barcelona, who go to Real Sociedad on Sunday.

"No goals, no luck and no explanation," said sports daily AS on their front page.

"Everything is going wrong," wrote editor Alfredo Relano in his column. "This result sinks Madrid further into the sombre mood that has invaded everyone, including Zidane."

If they had already all but given up on any hope of retaining the league title even before Saturday's game, there are now even concerns that they could miss out on a top-four spot altogether.

Real are eight points behind third-placed Valencia, who were 2-1 winners at Deportivo on Saturday. They are also only one point clear of Villarreal in fifth -- not since 2004 have they finished outside the top three in La Liga.

In Barcelona, the Catalan press seized the chance to stick the knife in.

"In crisis", headlined Mundo Deportivo below a picture of Cristiano Ronaldo, on the ground with his head in his hands.

Sport focused on the troubles in front of goal of Ronaldo, who missed numerous chances at the Santiago Bernabeu before Pablo Fornals' magnificent late winner for Villarreal, their first ever victory there.

Ronaldo has just four league goals this season, while Gareth Bale is struggling for fitness and form and Karim Benzema has been injured. The previously feared 'BBC' no longer carries the same aura.

"The white collapse is basically the collapse of Cristiano and, by extension, that of the whole 'BBC', a trident that died months ago now without anyone having realised," wrote Sport editor Ernest Folch.

Relano added: "Madrid started to fall behind because Cristiano was missing; then, because when he came back the goals were not going in; in the end, because the gap at the top provoked a disenchantment that shows."

Zidane is "an elegant coach but has no answers on the blackboard," according to Folch.

There is a danger that his position could become untenable if Madrid -- the two-time defending European champions -- lose to Paris Saint-Germain in the Champions League last 16, the first leg of which will be played at the Bernabeu on February 14.

Frederic Hermel, Madrid-based correspondent for French sports daily L'Equipe, noted that Zidane "still doesn't appear prepared to make any changes to his team, despite another defeat... (that) leaves a feeling of powerlessness."