Atletico Madrid failed to capitalise on LaLiga's top three all dropping points on Saturday, as they were held to a 0-0 draw at home to in-form Espanyol.
Diego Simeone's men were looking to make the most of third-place Sevilla losing and Barcelona and Real Madrid drawing in El Clasico, but they could not get the better of Espanyol's stubborn defence and ultimately had goalkeeper Jan Oblak to thank following a couple of essential saves.
The two sides played out a turgid first half in which the only real goal-scoring opportunity fell to the visitors, with Oblak thwarting Gerard Moreno just before the break.
Atletico initially failed to produce much of an improvement after the restart and were again indebted to Oblak just before the hour mark, as he kept former Atletico striker Leo Baptistao at bay when one-on-one.
The uncharacteristically quiet Antoine Griezmann went close with just over quarter of the match to go, but Espanyol - who had not conceded in any of their last four league games - looked impregnable at the back.
Their defensive solidity was tested in the final stages when Atletico threw men forward in desperate fashion, but they held out for a commendable point on Quique Sanchez Flores' return to the Vicente Calderon, leaving Atletico fourth and two points behind Sevilla.
Atletico dominated possession right from the start and put Espanyol under prolonged pressure, but the visitors rarely looked stretched and coped well.
The home side lacked cutting edge through the middle and only managed to test Diego Lopez once in the first half an hour, as Kevin Gameiro latched on to a pass and shot straight at the untroubled goalkeeper from a tight angle on the right edge of the penalty area.
That proved a rare sight of goal for Atletico, with Espanyol defending brilliantly and sitting very deep, looking to catch them on the break.
Sanchez Flores' men almost took the lead just before the interval, but Oblak made a crucial save to deny Moreno after Baptistao had played the Spaniard into the penalty area.
Espanyol began the second half with similar encouragement and had Atletico in some trouble in the 50th minute, as Pape Diop met Pablo Piatti's corner with a header that forced Diego Godin to desperately scramble the ball just over his own goal.
Atletico continued to dictate the tempo, but they looked susceptible on the counter and Espanyol should have broken the deadlock shortly afterwards - Oblak coming out on top in a one-on-one with Baptistao after Moreno had played in his strike partner.
Atletico finally upped their intensity after that let-off and went close themselves a few moments later.
Lopez parried Gabi's 25-yard effort away and then Griezmann's effort on the rebound flashed right across the face of goal.
Their attacks became more purposeful as the full-time whistle approached and Griezmann should have done better five minutes from time - but the Frenchman scuffed a left-footed effort straight at Lopez after Yannick Carrasco's cut-back as Espanyol held on to go eight unbeaten in LaLiga.