Espanyol have made it eight games unbeaten in La Liga after holding Atletico Madrid to a goalless draw in Saturday night's clash at the Vicente Calderon.
Victory for Atletico would have taken them level on points with third-placed Sevilla and to within one point of second-placed Barcelona, but Diego Simeone's side remain fourth following the stalemate.
Atletico, who are now nine points behind league leaders Real Madrid, had a penalty shout in the fifth minute after Antoine Griezmann's powerful strike hit Javi Fuego's arm inside the Espanyol box, but it would have been very harsh and the referee waved play on despite the Frenchman's protests.
Yannick Ferreira Carrasco shaped a cross into Kevin Gameiro as Atletico's first chance of the match arrived in the ninth minute, but the Frenchman could not make contact and Espanyol stopper Diego Lopez was on hand to collect.
Gabi was next to try his luck for the home side in the 18th minute, but Diego Lopez made another comfortable save, before Jan Oblak was called into action to keep out Gerard Moreno's low strike down the other end.
Atletico were frustrated for long spells of the first period and they actually almost fell behind in the 43rd minute, with only a smart save from Oblak preventing Moreno from finding the back of the net at the conclusion of a swift Espanyol counter-attack.
It was a similar story at the start of the second period as Espanyol, in a strict 4-4-2 formation, continued to frustrate the home side with an impressive rear-guard action, while Moreno and former Atletico striker Leo Baptistao were offering a threat down the other end of the field.
Indeed, Baptistao had a glorious chance to send Espanyol ahead on the hour after collecting a smart pass from Moreno, but Oblak made his second big save of the night to prevent Atletico from falling behind.
Diego Lopez then had to make a brilliant stop down the other end as the Espanyol goalkeeper flew across his goal to prevent a long-range Gabi strike finding the bottom corner and Gameiro could not turn the rebound home.
Griezmann and Jose Gimenez were next to come close for Atletico in the period that followed, but Espanyol kept their clean sheet intact entering the final 20 minutes of action in the Spanish capital.
Griezmann had a golden chance to win it five minutes from time when Nico Gaitan found the Frenchman unmarked inside the Espanyol box, but the attacker could only fire straight at Diego Lopez and the away side survived a late onslaught to continue their fine run of form under Quique Flores.
Next up for Atletico is their final Champions League group match away to Bayern Munich on Tuesday night, before visiting Villarreal in the league on December 12. Espanyol, meanwhile, will look to continue their rise up the table when they welcome Sporting Gijon on December 11.
