Celta Vigo caused an upset at the Vicente Calderon on Wednesday night by sealing a 3-2 victory over Atletico Madrid to send themselves into the semi-finals of the Copa del Rey for the first time in 15 years.
Pablo Hernandez scored twice and John Guidetti netted a stunning 30-yard strike for the visitors, cancelling out Antoine Griezmann's first-half equaliser.
Second-half substitute Angel Correa gave the hosts a glimmer of hope when he found the back of the net in the 82nd minute, but there was too much for Diego Simeone's side to do to get the result that they needed.
Inside the first 30 seconds of the game, Celta showed intent when Daniel Wass charged down the left side of the final third, heading for the byline, but despite putting Juanfran under pressure, the midfielder was unable to get a cross on.
Not long after, it was Atletico's turn to pile on some pressure as they earned two successive corners, the second of which almost produced a goal for Koke.
The ball was initially defended when it was whipped into the area, but it bobbled into the path of Koke, whose shot struck the ground first before going wide of the target.
Minutes later, Griezmann aimed a long-range strike to the centre of the goal and he got a slice of luck when goalkeeper Ruben Blanco spilled it, but when Luciano Vietto charged in to pick up the loose ball, he scraped his boots across the keeper's chest and gave away a foul.
Simeone's side continued on the attack as Saul Niguez drove into the box and showed some decent skill by passing the ball around Sergi Gomez before collecting it and aiming a shot towards the far post, but Blanco made the save.
Against the run of play, Celta took the lead in the 22nd minute when Fabian Orellana picked up the ball from the short corner and lifted it into the box onto the head of Pablo Hernandez, who nodded it home.
Atletico were able to respond, though, as Yannick Carrasco moved to the edge of the box before unleashing an effort on goal - the keeper managed to get a touch, but instead of pushing the ball clear, it was picked up by Griezmann on the rebound and he slid it into the net.
After the break, the game was evenly poised, but Celta ramped up the pressure and were eventually rewarded after having a goal disallowed for the ball going out of play.
It was a stunning strike from former Manchester City forward Guidetti, who picked the ball off Nemanja Radoja after it was robbed from Gabi in midfield. The Sweden international unleashed a shot from 30 yards out and it curled into the back of the net.
At 2-1 down, Atletico were on the ropes, but it went from bad to worse when Celta added another to their tally. Hugo Mallo was given plenty of time and space to send a cross into the area for Hernandez, who headed home for his second goal of the night.
The home side had a mountain to climb and it looked like an unlikely comeback when Vietto summed up the team's night - he fluffed an opportunity by attempting a weak shot at goal that was comfortably handled by the goalkeeper.
Atletico managed to pull one back through Correa, who dodged past three defenders before drilling the ball into the bottom right corner, but it was not enough to inspire a comeback.
