Diego Colotto's first goal for Espanyol handed the Catalans their first away win of the campaign and moved them out of the relegation zone for the first time this season as they beat Real Sociedad 1-0.
It was the home side who carried the greater threat for the first hour as Imanol Agirretxe was denied by a goal-line clearance by Sergio Garcia and Asier Illarramendi saw a spectacular 30-yard volley turned over by Cristian Alvarez.
However, the Basques were made to pay for their profligacy in front of goal and were hit with a sucker punch 12 minutes from time as Colotto was on hand to tap home after Hector Moreno had kept the ball alive from Joan Verdu's corner.
A fourth loss in five games had the home fans calling for manager Philippe Montanier's resignation by the final whistle, but in truth defeat was harsh on his side who missed the invention of top-scorer Antoine Griezmann due to a muscle injury.
Even without the French Under-21 international though the hosts started brightly and Alvarez had to make a good low save to his right to turn away a flicked header from Xabi Prieto.
Agirretxe was next to threaten and after appeals for handball were waved away after Garcia had turned his goalbound header behind, the striker had another fine effort across goal that was tipped round the post by Alvarez.
Garcia himself then had Espanyol's best effort of the first half from a well worked free-kick that Eqaut Zubikarai got down bravely to save.
A wonderful piece of technique from Illarramendi nearly gave the hosts a deserved lead just before the break as he took a looping ball first time on the volley and forced another great save from Alvarez.
The pattern remained the same after the break as Sociedad pushed for an opener but after weak efforts straight at Alvarez by Agirretxe and Inigo Martinez their momentum faded and Espanyol took advantage with virtually their only chance of the second period.
Moreno had actually fallen to the floor in his attempt to get on the end of Verdu's corner but still managed to prod the loose ball goalwards and Colotto was waiting to apply the easiest of finishes.