Atletico Madrid were dumped out of the Copa del Rey at the quarter-final stage for the second season running after Celta Vigo won 3-2 at Vicente Calderon.
Chilean midfielder Pedro Pablo Hernandez scored a pair of headed goals either side of John Guidetti's thunderbolt to give Celta only their second victory over Atletico in the last six meetings between the two sides.
Goals from Antoine Griezmann and Angel Correa turned out to be meaningless in the second leg - the first encounter having finished 0-0 - for Atletico, whose unbeaten run of eight matches in all competitions came grinding to a halt on a night they will want to forget.
Defensive errors have not been a problem for Diego Simeone's side this season, but his players were caught napping at the back throughout a contest that Celta deservedly won with a courageous performance.
Celta move through to the semi-finals, where they will hope to secure a passage to their first Copa del Rey final in 15 years.
Having been held to goalless draws in both of their previous matches, Atletico started the game with a sense of urgency and Koke hammered a shot just wide from Yannick Ferreira Carrasco's corner after five minutes.
The expectant Vicente Calderon crowd urged their side forward and Griezmann fired a deflected shot that was saved by Celta goalkeeper Ruben Blanco, who required treatment after Luciano Vietto clattered into him in an attempt to follow up the effort.
Celta had barely ventured beyond the halfway line when Guidetti's corner found Fabian Orellana, whose looping cross was met with a powerful header into the net by the unchallenged Hernandez to make it 1-0 after 22 minutes.
It took just seven minutes for Atletico to level the match and the equaliser was cruel on Blanco, who saved Carrasco's long-range shot brilliantly but the rebound fell to Griezmann and the Frenchman made no mistake tucking away the rebound.
Blanco's first-half endeavours left him unable to continue and he was replaced by Sergio Alvarez, whose first task was to watch Vietto flash a shot just wide of his post from Juanfran's cross.
At the other end, Hernandez thought he had put Celta 2-1 up when he slotted Guidetti's cross into an empty net with Moya stranded, but the ball was judged to have gone out of play before the cross came over.
Guidetti made no such mistake moments later when he collected a loose ball and thumped it into the net from all of 25 yards to put Celta ahead on the night with two away goals.
Substitute Correa slammed a shot onto the crossbar as Atletico looked to haul themselves back into the contest, but Celta immediately surged forward again and Hugo Mallo crossed for Hernandez to score his second unmarked header of the evening.
Correa jinked through a crowded penalty area to score a brilliant solo goal after 81 minutes, but it was to be nothing more than a consolation for Atletico.