Osasuna have dealt a major blow to Atletico Madrid's La Liga title aspirations courtesy of a shock 3-0 victory over the high-flyers.
The hosts took the lead after just six minutes when a well-worked corner allowed Alvaro Cejudo to steal into the area unmarked and drill a low strike past Thibaut Courtois.
Osasuna doubled their lead 15 minutes later when Emiliano Armenteros worked space outside the box before unleashing an effort into the top corner.
Atletico had a good chance to pull a goal back shortly after the half-hour mark, but Mario Suarez failed to connect with Gabi's cross despite arriving unmarked into the box.
The visitors were then further stunned by a third Osasuna goal before half time, Roberto Torres nodding home a Damia cross from close range to give his side a shock 3-0 lead at the break.
It could have been four with a little over 15 minutes of the match remaining when Torres picked out Cejudo inside the box, only for the winger to smash his effort into the side-netting.
The Madrid outfit almost raised hopes of an unlikely late comeback with 10 minutes left as Arda Turan's cross found Raul Garcia, but the Spaniard could not steer his effort on target.
Diego Costa crafted an opening for himself late on, dancing into the area only to send his eventual shot high and wide of the crossbar.
The visitors could not register on the scoresheet, however, as Osasuna held out for a remarkable victory that leaves Atletico three points behind leaders Real Madrid.
