Barcelona were stunned for the second straight season at Celta Vigo on Sunday, falling 4-3 in their La Liga clash at the Estadio Balaidos.
The home side, who similarly surprised the Blaugrana 4-1 back in September of last year, jumped out to a three-goal advantage with an 11-minute flurry midway through the first half.
Pione Sisto (on 22 minutes), Iago Aspas (in the 31st) and a Jeremy Mathieu own goal left Luis Enrique's side in a hole from which they couldn't recover. Pablo Hernandez's close-range header of a inexplicable Marc-Andre ter Stegen pass from his own goal-mouth added the fourth for Eduardo Berizzo's men.
A brace from Gerard Pique and a converted Neymar penalty kept the Catalans close, but they could not spoil the satisfying victory for Celta on the night.
The loss keeps Barca, who missed a chance to top the table with a victory, on 13 points for the young season, two back of leaders Atletico and Real Madrid. While the result helps Celta go further clear of the relegation zone with 10 points.
Real Madrid missed the chance to move back to the top of the Primera Division table as they drew 1-1 at home to Eibar.
Atletico Madrid had leapfrogged their rivals earlier on Sunday, but Real were unable to move two points back in front of them and needed a Gareth Bale equaliser to earn them the draw.
Eibar took only six minutes to open the scoring, with Fran Rico heading home an Ander Capa delivery to stun the home crowd, but Real levelled in the 17th minute when Bale headed Cristiano Ronaldo's cross beyond Asier Riesgo.
Bale and Ronaldo spurned chances after the break as Eibar held on for a point.
Atletico Madrid beat Valencia 2-0 at the Mestella despite an outstanding performance by home goalkeeper Diego Alves.
Alves, La Liga's record penalty-saver, stopped another two spot-kicks as he denied Antoine Griezmann and Gabi, also making a string of other good saves.
But the Brazil international was beaten when Griezmann made the breakthrough in the second half, and Kevin Gameiro put Atleti's win beyond doubt in stoppage time.
Villarreal remain unbeaten after securing a 0-0 draw away to Espanyol.
The Yellow Submarine's journeys this week had taken them from Bucharest, where they drew 1-1 with Steaua in the Europa League on Thursday night, to Barcelona and a point apiece with Quique Sanchez Flores' men was probably the correct result on the balance of play.
Espanyol edged out of the relegation zone with the point, but still have just one win to their name after seven matches.
Malaga lifted some of the pressure on under-fire coach Juande Ramos as they came from behind late on to beat Athletic Bilbao 2-1 at La Rosaleda.
The Basque side had reeled off four successive league wins coming into this game and an assured finish from Aritz Aduriz in the third minute looked like it would set up another.
But the pivotal moment was the red card shown to Athletic full-back Mikel Balenziaga, who retaliated when Roberto Rosales left a boot in on him after a defensive clearance.
Balenziaga may face further sanction after remonstrating with the referee for several minutes before departing, and his team-mates were unable to hold on without him as quickfire goals inside the last 10 minutes from Sandro Ramirez and Duda earned the Andalusians just their second win in seven league matches.
The home side also finished with 10 men as defender Bakary Kone was sent off in the dying seconds.