Gerard Moreno's penalty condemned Real Madrid to their second LaLiga defeat of the season as Villarreal beat the champions 2-1 on Saturday to do coach Quique Setien's former employers Barcelona a favor.
Madrid had hoped to return to the summit ahead of Barca's tough trip to Atletico Madrid on Sunday, but Villarreal were good value for victory during a thriller at Estadio de la Ceramica.
Villarreal created a host of promising openings during an entertaining first half but had to wait until just after the break to make the breakthrough thanks to Yeremy Pino.
Karim Benzema leveled with a spot-kick conceded by Juan Foyth on the hour mark, but the Argentinian then won one at the other end, with Moreno's confident finish ultimately sealing the win.
Villarreal had been the better side right from the start, going close after 28 seconds as Alex Baena sliced over. Francis Coquelin then saw an impudent backheeled finish clip the post following Alberto Moreno's low cross four minutes later.
Villarreal were indebted to Jose Reina just before the break, however, rushing out to deny Vinicius Junior.
The Yellow Submarine capitalized 65 seconds after the restart as Gerard Moreno released Yeremy into the box, his finish finding the net via deflections off Courtois and David Alaba.
Benzema spurned a glorious chance to level when Foyth blocked his goal-bound effort on the line, but the Frenchman made the most of his penalty reprieve after the defender's handball in the build-up was punished following a VAR review.
Villarreal went straight up the other end and won a penalty of their own moments later, though, Foyth seeing his pass handled by Alaba, and Moreno made no mistake.
Madrid's desperation led to Courtois going forward for a late corner and Arnaut Danjuma almost made it 3-1 on the break, though his inability to score into the empty goal did not matter.