Real Mallorca recorded their first away win at Espanyol in over a decade with a 2-1 comeback win at the Cornella-El Prat thanks to second half goals from Pierre Webo and Emilio Nsue on Tuesday.
Fifth-placed Espanyol had taken an 18th minute lead through Alvaro Vazquez but Cameroon forward Webo headed an equaliser on 62 minutes and Nsue netted the winner eight minutes from time as the islanders won at Espanyol for the first time since 2000.
It is a major setback for Espanyol's European hopes and Athletic Bilbao, two points behind in sixth, can move above them with a win at Real Zaragoza on Wednesday.
For Mallorca it was only their third away win of the season as they move four points off the top six.
With just seven minutes gone Mallorca won a penalty with centre-back Jordi Amat clipping Webo in the box.
Chori Castro stepped up but goalkeeper Carlos Kameni guessed the right way and got down low to palm away the spot-kick.
A minute later Espanyol went down the other end and Jose Callejon crashed a shot against the post in a thrilling opening.
The hosts got the breakthrough on 18 minutes with Mallorca getting their offside trap horribly wrong as Vazquez bent his run before keeping a cool head to slot home.
Mallorca thought they had equalised on the half hour mark but Webo's header was harshly ruled out for offside.
Livewire Webo got the goal his performance deserved with a header to level the scores just after the hour mark.
Winger Nsue then popped up with a late 82nd minute winner as Mallorca took the spoils.
Later on Tuesday Sevilla host Sporting Gijon aiming to fight through the fatigue barrier and boost their hopes of a top six finish.
It will be Sevilla's fourth game in nine hectic days and Sporting, one point above the relegation zone, will aim to take advantage.
Barcelona have a tough trip to third-placed Valencia on Wednesday as they bid to stretch their seven-point lead over Real Madrid.
"Going back to a seven point lead is not important, because there are lots of points at stake," said Barcelona defender Dani Alves. "Collectively we're better than them (Real Madrid) and if we carry on like we are we'll meet our objectives."
It will be a special game for Barcelona striker David Villa who returns to Valencia for the first time since his 40 million euro move in the summer.
Real Madrid host lowly Malaga on Thursday looking to bounce back from their disappointing 0-0 draw at Deportivo La Coruna with a 13th win at the Santiago Bernabeu.
Malaga, second from bottom of the table, are coached by former Real boss Manuel Pellegrini who managed the club last season but a club record 96 points saw them finish runners-up to Barcelona and the Chilean was axed.
"I'm quite proud of what I achieved with Real Madrid," said Pellegrini. "Football allowed me to enjoy the most successful league campaign in the history of Madrid."