Celta Vigo stunned Atletico Madrid to bring the champions back down to earth after last week's demolition of Real Madrid, winning 2-0 at Balaidos thanks to two second-half goals.
Nolito converted a hotly-contested penalty in the 58th minute and Fabian Orellana then sealed the points for the Galicians with a thumping drive.
The defeat means Diego Simeone's side are in the same position as before their dream derby win - third in the Primera Division and seven points behind Carlo Ancelotti's side - while Celta put further distance between themselves and the relegation zone and moved up to ninth in the table.
Eduardo Berrizo's side had held Atletico to a 2-2 draw at the Vicente Calderon at the start of the season - one of just two teams to take points off them at home this season - and played with more intensity than the champions in the first half at Balaidos without creating too many clear chances.
The key moment in the game arrived 12 minutes into the second half, when Nolito tried to round Mario Suarez in the area and tripped over his trailing leg. Atletico were particularly furious at the decision, also claiming that Augusto Fernandez had handled the ball before entering the box. However, Nolito kept his cool from the spot and slotted into the bottom corner.
Mario Mandzukic tried to respond immediately for the visitors by shooting at goal from 25 yards, but Sergio Alvarez made a fine save to keep his side ahead.
Joaquin Larrivey should have killed the game off a moment later, arriving at the far post to meet Nolito's cross but failing to properly connect with the ball.
Atletico were not about to throw in the towel either, and Alvarez had to fling himself at the near post to prevent Antoine Griezmann's powerful effort squeezing in.
But Celta refused to simply sit back and soak up the pressure and instead kept on looking for the second goal, which they found with 19 minutes left.
Michael Krohn-Delhi strolled towards the area unopposed and played in Orellana on the right hand side of the box, and the Chilean arrowed the ball into the far corner.
Atletico still refused to give up, but this was never meant to be their day, as was demonstrated when they were denied a penalty as Guilherme Siqueira was kicked in the thigh by Andreu Fontas, and later when Mandzukic sent a free header straight into Alvarez's hands.
Earlier in the day, Lionel Messi scored a hat-trick in his 300th Primera Division match as Barcelona thumped Levante 5-0.
Neymar opened the scoring, with Messi adding the second in the 38th minute as Barcelona looked totally comfortable against their lowly opponents.
The Argentina striker added his second and Barcelona's third in the 59th minute as Luis Enrique's side continued to dominate the match.
Messi then completed his hat-trick from the penalty spot in the 65th minute before Luis Suarez added the gloss with a fifth goal courtesy of a bicycle kick.
The win means Barcelona are now back to within a point of Primera Division leaders Real Madrid, who defeated Deportivo La Coruna 2-0 on Saturday.
Messi was key in four of Barcelona's goals - creating the first for Neymar before scoring a hat-trick himself.
The home side dominated the match throughout and claimed an early lead when Messi found some space after cutting inside before finding the run of Neymar at the back post, who took the ball first-time on the volley to loop it over Levante keeper Diego Marino in the 17th minute.
Messi then handed the home side a 2-0 cushion before the break when defender Marc Bartra won the ball in midfield then released the striker, who made no mistake with a low strike into the bottom corner.
Messi squandered the chance to put Barca 3-0 up ahead of half-time when he opted to shoot from the edge of the box instead of playing in Brazilian Neymar, who was totally unmarked a few yards out. Messi's shot went wide but the home side were well in control.
The diminutive striker was on target, though, just before the hour mark to wrap up victory for his side when Sergio Busquets chipped a pass over the Levante defence, where Pedro was waiting to lay a volley into the path of Messi, who slotted his second.
Neymar then won a penalty when he was brought down by Levante right-back Ivan Lopez, with Messi stepping up to fire in from the spot to complete his hat-trick.
Barcelona did not take their foot off the gas, with Suarez claiming their fifth goal in the 73rd minute when he was on hand in the middle of the box to bicycle-kick Adriano's pull back from the byline past Marino.
Messi was denied his fourth by Marino five minutes from the final whistle when the Levante keeper tipped his left-footed half-volley over the bar.
Elsewhere this evening second half goals from Alberto Bueno and Gael Kakuta saw Rayo Vallecano beat Villarreal 2-0 to pick up their first home victory in almost three months.
The win brought a welcome end to a three game losing streak for the Madrid outfit, widening the gap between them and the relegation zone to seven points.
