Barcelona were held 0-0 at Espanyol to cede the provisional lead of the Spanish league to Atletico Madrid on Saturday, after Diego Simeone's side got some late heroics from substitute Thomas Partey for the second time in four days.
Partey went on in the 73rd minute with Atletico struggling to find the net at home against Levante after hitting the woodwork three times. Eight minutes later, he executed a superb dribble to slalom past three defenders before goalkeeper Diego Marino spilled his shot over the goalline to snatch a 1-0 win over the last-place visitors.
"Once again, the changes gave us the boost we needed, above all Thomas with his decisive run," Simeone said.
The victory lifted Atletico two points ahead of Barcelona, which still has a game to play.
Barcelona's Lionel Messi and Luis Suarez were also denied by the goalframe as the defending champions drew for a third time in four rounds after being kept in check by crosstown rival Espanyol.
Atletico was again plagued by the same lack of finishing touch that its strong defending has compensated for to keep it in the title chase.
Stefan Savic, Jorge "Koke" Resurreccion, and Luciano Vietto all found the crossbar before Partey finally unlocked the Levante defense with his audacious move right through the center of the area.
Partey didn't debut this season until late November, but his contributions off the bench in his last two games have proven critical. As a second-half substitute on Wednesday, the midfielder from Ghana set up its 87th-minute opener in a 2-0 win at Rayo Vallecano.
"I still need to learn more things, and that with my work my minutes are coming," Partey said.
Espanyol succeeded where 30 consecutive league rivals had failed, to hold Barcelona scoreless. The last opponent to do so was Malaga in a 1-0 win over Barcelona on Feb. 21 last season.
Espanyol also ended a run of 11 straight games of at least one goal from a member of Barcelona's strike trio of Messi, Suarez and Neymar, who combined for 137 goals in 2015.
"They played well and with the intensity we expected," Barcelona coach Luis Enrique said. "Espanyol always plays with that level of physicality, and it is always easier to destroy than create. The result was fair given what both teams generated, even though we had our chances."
Barcelona's slip, which came after draws at Valencia and against Deportivo La Coruna - followed by a victory over Real Betis in the last round - also let Real Madrid stay close. Third-place Madrid trails Barcelona by three points before visiting Valencia on Sunday.
Espanyol's pressure disarmed Barcelona's talented attack for most of the match.
"We have drawn against the best team in the world," said Espanyol coach Constantin Galca, whose team provisionally edged into 12th place after his third match in charge.
"I'm satisfied with our work in defense, but we are still lacking in attack," the former Espanyol player said. "We have to create more scoring chances."
In one of its most subdued halves this season, Barcelona could seriously threaten Pau Lopez's goal only late in the first half when Messi earned a foul and proceeded to curl his free kick off the corner of the goalframe.
The tone changed briefly after halftime when Suarez dribbled through the area and laid off for Neymar, whose shot from close range was blocked by defender Victor Alvarez.
Suarez squandered a great opportunity when he struck the upright from an angle after dribbling past Lopez in the 55th.
Barcelona won't have to wait long to avenge the lost points. The Catalan capital's first-division teams will play again in the round of 16 of the Copa del Rey on Wednesday and Jan. 13.
"We didn't play well, but these derbies are played to the limit, and we have taken note for the cup," Barcelona's Andres Iniesta said. "We keep adding up points, we have a game in hand, and there is a long way to go. This isn't a setback."
Malaga also beat Celta Vigo 2-0 for a fourth straight win as it rose into 10th place.