Real Madrid were left shell-shocked by a clever last-gasp Pablo Fornals goal as Villarreal earned a smash-and-grab 1-0 win at the Santiago Bernabeu.
LaLiga's champions largely dominated proceedings on home soil, but Villarreal snatched all three points and a first league victory at Madrid with three minutes left thanks to Fornals' exquisite chip after Enes Unal's shot was saved.
It compounded a day of utter frustration for an out-of-form Madrid, who felt they twice should have had a penalty in the first half.
Villarreal defender Alvaro Gonzalez was lucky to not face punishment for handball from a Gareth Bale header, while Cristiano Ronaldo was adamant he was fouled by Mario Gaspar on the stroke of half-time.
Referee Alberto Undiano Mallenco was unmoved on both occasions, while Madrid were further frustrated by a poor one-on-one miss by Ronaldo and some good work by Villarreal goalkeeper Sergio Asenjo.
Madrid have now won just once in five LaLiga matches and will be 19 points adrift of Barcelona if their Clasico rivals beat Real Sociedad on Sunday, while Villarreal are just one point adrift of Los Blancos in their bid to muscle in on the top four.
Isco saw an early effort blocked by Gaspar, with the Spain playmaker's tentative penalty claims for handball rightly going unheard.
Bale saw a goal ruled out after nodding in from Ronaldo's header back across goal, before Asenjo made a fine stop from Marcelo's rasping 35-yard drive.
He made an even better stop to palm Ronaldo's 25-yard dipping free-kick over the top via the crossbar, before the Portugal captain wastefully dinked over Asenjo and wide of the left post after latching onto Luka Modric's throughball.
Ronaldo went close again shortly after when he hit a stinging drive into the side-netting.
Madrid were unfortunate not to be awarded a penalty 10 minutes before half-time when Bale's header from Toni Kroos' left-wing cross was seemingly handled by Alvaro Gonzalez. And Madrid had more cause for consternation on the stroke of half-time.
Isco's teasing low cross was met by Ronaldo inside the six-yard box and saved brilliantly by Asenjo, but the forward was seemingly clipped by Gaspar when meeting the ball.
Villarreal brought Denis Cheryshev on as a half-time substitute and the former Madrid winger picked Casemiro's pocket before dragging wide from the edge of the box.
A lively start to the half saw Raphael Varane make a crucial intervention from Samu Castillejo's probing pass, while Asenjo was equal to a well-controlled Kroos volley.
Modric saw a 20-yard daisycutter well held by Asenjo, while the Croatia midfielder hit a fierce drive over the top from outside the area with 10 minutes remaining.
And Madrid were made to rue their lack of clinical edge in the 87th minute.
Villarreal launched a lightning counter-attack led by Cheryshev, who slipped in Unal and, although his shot was saved by Keylor Navas, Fornals was on hand to brilliantly clip his shot over the stranded Madrid goalkeeper to spark jubilant scenes on the away bench.
Key Opta stats:
- Real Madrid attempted 28 shots against Villarreal, the most for a team in a LaLiga game this season.
- Villarreal have won for the first time in their 18 league visits to Santiago Bernabeu (D5 L12)
- Isco has been substituted more times than any other Real Madrid player in LaLiga this season (10)
- Real Madrid have not won in five home games in LaLiga this term (D2 L3), the same as in the whole of last season (D4 L1) and more than in any other LaLiga season since 2006-07 (D4 L3).
|Curry, Durant lead Warriors past Thunder|
|Kjaer surprised by LaLiga-leading Sevilla as Machin´s men remain grounded|
|A-League preview: Honda the big arrival as fascinating season awaits|
|Mexico 0 Chile 1: Sanchez helps La Roja to late win|
|Celtics too good for 76ers in NBA opener|
|United States 1 Peru 1: Flores salvages late draw for visitors|
|Martinez not worried about Belgium depth|
|Red Sox move ahead of Astros in ALCS|
|Depay ´a joy to watch´, says Koeman|
|Timberwolves owner looking to trade Butler, backs Thibodeau|
|Shepard says Giants have ´total faith´ in Manning|
|Hazard is out of this world – De Ligt enjoys Belgium test|
|Tite: Brazil were better than Argentina|
|Foley eyes World Cup after re-signing with Wallabies, Waratahs|
|Low slams decisive France penalty call|
|I fined him for his goal at Old Trafford! Giggs delighted for Wales hero Wilson|
|Matuidi lauds Deschamps´ tactical nous after Germany win|
|Scaloni excited by Argentina despite Brazil loss|
|Tsonga back in business, Dzumhur dumped out in Moscow|
|Germany suffer six defeats in a year for first time|
|Many clubs have asked about Piatek - agent|
|Bartomeu: Barca open to defensive reinforcements after Vermaelen injury|
|Bonn spoil PAOK´s landmark European game|
|Konta conquers Mertens in Moscow|
|Republic of Ireland 0 Wales 1: Wilson stunner moves Giggs´ side top|
|France 2 Germany 1: Griezmann delivers Low blow as Les Bleus reign in Paris|
|Belgium 1 Netherlands 1: Groeneveld cancels out Mertens strike|
|Argentina 0 Brazil 1: Miranda heads late winner after rivalry fails to ignite|
|Messi would struggle in this Manchester United team – Scholes|
|Falcons place Devonta Freeman on injured reserve|
|Westbrook ruled out of Thunder opener|
|Wilder´s team open to Joshua talks|
|Brentford appoint Thomas Frank as new head coach|
|England´s perfect performance sets the standard - Trippier|
|Odell Beckham Jr. needs to create headlines on the field, says Giants owner|
|Robshaw joins list of England absentees|
|Chile need goals from Sanchez despite United form - Rueda|
|Modric reveals Ronaldo respect, ´will never play with´ Messi|
|Osaka can be one of the greats, says coach Sascha Bajin|
|Liverpool´s Naby Keita carried off injured in Guinea match|
|Duminy to miss Australia tour for shoulder surgery|
|F1 Raceweek: Ferrari ready to ´challenge the impossible´ as Hamilton nears title|
|Umesh replaces injured Thakur in ODI squad|
|IAAF delay implementation of testosterone ruling amid Semenya challenge|
|Fakhar and Sarfraz lead Pakistan recovery after Lyon blitz|
|Japan see off Uruguay in seven-goal thriller|
|Arda Turan given huge fine by Istanbul Basaksehir after alleged brawl with singer|
|Busquets no better or worse than Dier – does Opta data back up Allardyce claim?|
|United boss Mourinho charged for alleged post-match comments by FA|
|Halep withdraws from Kremlin Cup ahead of WTA Finals|
|Renato Sanches eager for further Bayern Munich minutes|
|Nations League standings: Promotion, relegation and race for finals|
|Windies coach Law banned for ´inappropriate comments´ in India Test|
|Carrick denies Manchester United stars are ´not trying´|
|Ferrari struggling under pressure of chasing Mercedes, says Massa|
|Australia desperately need Smith and Warner back - Warne|
|Draxler warns Germany: Mbappe has 300 hp!|
|Draymond Green says Warriors will have to ´bring it´ every night in the West|
|England´s ´wonderful bravery´ leaves Southgate excited for the future|
|Jayasuriya: I always conduct myself with integrity and transparency|
|Northern Ireland stars hurt by lack of club football, says O´Neill|
|Rodgers inspires late Packers comeback|
|Brewers blank Dodgers to take 2-1 NLCS lead|
|Cavaliers, Nance agree to four-year extension|
|Ramos wants Spain to believe in Luis Enrique´s team|
|De Laurentiis: I´ve spoken to Genoa and agent about Piatek|
|Kaka tips bright future for Paqueta after Milan agreement|
|Suns star Booker set to return for season opener|
|Warriors coach Kerr not expecting fast start from NBA champs|
|Fultz to start for 76ers as Brown eyes NBA Finals|