A first-half strike from Radamel Falcao was enough to hand Rayo Vallecano a shock 1-0 win over Barcelona on Wednesday as the Catalans slumped to their second successive La Liga defeat.
Following their defeat by rivals Real Madrid over the weekend, Wednesday's result was the last straw for coach Ronaldo Koeman. He was later sacked with his side having won only two of their last seven league games and lying ninth in the standings with 15 points.
Colombian striker Falcao pounced in the 30th minute after Barca captain Sergio Busquets lost the ball in midfield and allowed Rayo to launch a quick counter-attack that led to the goal. After dribbling past Gerard Pique, Falcao finished off in style.
Barca had a great chance to equalise in the 72nd minute but Rayo goalkeeper Stole Dimitrievski saved Memphis Depay's penalty.
Borussia Moenchengladbach sensationally struck three times in the opening 21 minutes to demolish German champions Bayern Munich 5-0 and dump them out of the German Cup second round.
Gladbach's dream start yielded two goals fro Ramy Bensebaini and one from Kouadio Kone to put them in the driving seat before Breel Embolo struck twice early in the second half to kill off the game.
They became the first team to score five goals against the mighty Bavarians since Borussia Dortmund's 5-2 win in the 2012 German Cup final, and the first ever team to score three goals in the first 21 minutes against Bayern in a German Cup game.
They needed just 80 seconds to open their account with Kone pouncing on a sloppy pass by Bayern's Alphonso Davies to beat keeper Manuel Neuer.
With the Bayern defence in complete disarray, the hosts should have scored again with Jonas Hofmann and Embolo coming close as the defensive efforts by the visitors piled up.
Gladbach did it better in the 15th, outplaying the static Bayern backline for Bensebaini to thunder a Hofmann cutback past Neuer.
Before they had any time to recover Lucas Hernandez, who earlier on Wednesday had seen a six-month prison sentence suspended in Spain, clumsily brought down Embolo in the box and Bensebaini sent Neuer the wrong way with an audacious spot kick to make it 3-0.
With Bayern coach Julian Nagelsmann confined to his home after testing positive for COVID-19, assistant coach Dino Topmoeller had to wait until the second half to see some decent attacks from his players, who have netted a record 33 times in their first nine league games.
But before they even got into any rhythm, Gladbach struck again with Embolo beating two defenders, who let a high ball bounce between them, to slot the ball in through the legs of Neuer.
The Swiss bagged his second goal of the evening in the 57th, finding far too much space once more to score their fifth off the post.
In Serie A Juventus slipped to a shock 2-1 defeat at home to Sassuolo, with Maxime Lopez's stoppage-time winner stunning Massimiliano Allegri's side.
The hosts were well off the pace in the first half and fell behind to a fine team goal from Sassuolo two minutes before the break, with Davide Frattesi finishing well when put through on goal.
Juve stepped it up in the second half with Juan Cuadrado having a powerful effort cleared off the line while Federico Chiesa also missed with a header.
The equaliser finally came when McKennie powered a header into the net in the 76th minute, much to the relief of everyone in the Juventus Stadium.
Juve threw everything at Sassuolo to find a winner, but they were caught on the break in the 95th minute, as Lopez raced clear before lofting a fine finish into the net to secure victory for his team.
The surprise defeat dropped Juve to seventh in the standings with 15 points. They trail leaders AC Milan by 13 points after 10 games. Sassuolo climbed to ninth, a point adrift of Juve.