Villarreal's bid for a lucrative berth in next season's Champions League suffered a fresh blow when they twice had to come from behind to rescue a 2-2 draw at Racing Santander in La Liga on Sunday.
The club with the distinctive canary-yellow strip failed to build on their Europa League victory over Serie A side Napoli and have failed to win in their last four league games, losing twice and drawing at home to bottom club Malaga.
Their latest setback leaves them in fourth on 47 points, one behind third-placed Valencia, who play at Athletic Bilbao later on Sunday (2000).
In Saturday's games, Barcelona moved seven clear of second-placed Real Madrid after they won 3-0 at Real Mallorca and Real were held to a 0-0 draw at Deportivo Coruna.
Racing are undefeated since Indian businessman Ahsan Ali Syed completed his takeover of the club at the end of January and stay in 12th on 29 points, five clear of the relegation places.
They took the lead at a festive Sardinero stadium in the third minute when burly forward Ariel tapped in from close range, sparking wild celebrations from Ali Syed in the stands.
Villarreal's woes were compounded when coach Juan Carlos Garrido was sent from the bench early in the second half but they grabbed an equaliser in the 66th via a Marco Ruben header.
Racing substitute Giovani Dos Santos struck a superb goal two minutes later when he raced onto a Pedro Munitis pass and directed a low shot past Diego Lopez before striker Nilmar bundled home for the visitors in added time.
Valencia, undefeated in 10 league games, can stretch their lead over Villarreal to four points at sixth-placed Bilbao, who are looking to end a run of two successive defeats and can climb above Espanyol into fifth with a win.