Atletico Madrid had not lost at home since March 2013 but fell to a shock 1-0 defeat to Villarreal on Sunday night thanks to an 84th minute goal from Luciano Vietto.
Vietto left Diego Godin for dead before coolly slotting home after Mario Mandzukic had earlier had a goal disallowed for a push at the far post.
With Barcelona also dropping points in a 0-0 draw with Getafe on Saturday, Real Madrid head to the Club World Cup with a four-point lead at the top of La Liga -- seven now over champions Atletico.
Minnows Eibar made light of Sevilla's hugely impressive home record to claim a point from their trip to the Ramon Sanchez Pizjuan.
Sevilla are unbeaten in front of their own fans since March and had won nine of their 11 competitive matches on home soil this season -- including scoring in every match -- but they were unable to break down Eibar, who continue to impress in their debut season in the top flight.
Both sides had chances to score, while Sevilla staged a late assault on the visiting goal as they tried to snatch the winner, but in the end defences came out on top as the match finished 0-0.
A second-half equaliser by Athletic Bilbao's Oscar de Marcos denied David Moyes' Real Sociedad a much-needed win in the Basque derby.
Carlos Vela's early headed goal got hosts Real Sociedad got off to a dream start and Moyes' side missed several chances to extend their lead before half-time.
They were made to rue those misses when De Marcos equalised in the 62nd minute, meaning the game ended 1-1.
Athletic had to play the final 10 minutes with 10 men when Aymeric Laporte was sent off, but Real Sociedad were unable to make the extra man count, and remain 14th in the table. They are five points behind Athletic, who occupy 10th place.
Christian Stuani scored a last-minute winner for Espanyol as they claimed a 2-1 victory over 10-man Granada.
Felipe Caicedo opened the scoring for the hosts before the break with Youssef El Arabi levelling for Granada in the 61st minute.
El Grana defender Juan Carlos was sent off in the 82nd minute after picking up his second yellow card of the match, giving Espanyol an advantage and Stuani netted from close range with 30 seconds left on the clock.
The result means Granada are now winless in their last 11 Primera Division games while Espanyol bounced back from their 5-1 drubbing by Barcelona to claim two league wins from their last three.