Carlos Castro and Antonio Sanabria dented Atletico Madrid's faint title hopes with late goals to earn struggling Sporting Gijon a 2-1 victory in La Liga.
Second-placed Atletico, who are eight points adrift of leaders Barcelona, were uncharacteristically sluggish after their European exploits and Sporting made them pay late on with two goals in the final 11 minutes at El Molinon.
Atletico had looked on course to earn a slender victory after Antoine Griezmann's stunning first-half free-kick, the France international curling home his 17th of the league season.
However, the visitors struggled to create a chance of note in the second period and were ultimately punished by a Sanabria set-piece and Castro's late tap-in – the substitute having earlier hit the crossbar.
The win temporarily moves Sporting out of the bottom three and sends Diego Simeone's side to their first defeat in eight league matches, while handing Barcelona the chance to extend their lead when they meet Villarreal on Sunday.
Atletico – who made five changes from the side that battled past PSV on penalties in the Champions League this week – could have been ahead inside the first minute, but Griezmann lost his balance at the crucial moment.
Tuesday's exertions seemed to have an impact on the visitors after that, though, and Sporting took advantage with Sanabria and Jony posing a threat to Atletico's resolute back line.
For all Sporting's pressure, however, they were made to rue their profligacy when Griezmann fired Atletico in front just before the half hour.
After Pablo Perez had been penalised for a foul on Saul Niguez on the edge of the penalty area, Griezmann took full advantage with an inch-perfect free-kick that curled into the top-left corner beyond the despairing dive of Pichu Cuellar.
Sporting's struggles in front of goal continued to trouble them after the restart, with Sanabria and Lora both wasting good openings.
The hosts continued to enjoy large swaths of possession, but Simeone's side were able to soak up that pressure until Sanabria finally found a way through after seeing an earlier effort hit the post.
With 11 minutes to play, Matias Kranevitter gave away a needless free-kick on the edge of the penalty area and Sanabria punished him with a powerful effort that fizzed past Jan Oblak.
And Castro completed their comeback after 89 minutes as he tapped home Jony's low cross from close range, the substitute's blushes spared having hit the bar with a similar chance moments earlier.
