Atletico Madrid dominated their bitter rivals Real Madrid running out 4-0 winners to throw the Spanish title race wide open.
Four different players found the net for Atletico at the Vicente Calderon Stadium to beat an injury-hit Real Madrid. The win leaves Atletico four points down on Carlo Ancelotti's team and level with Barcelona, who play against Athletic Bilbao on Sunday evening.
Tiago Cardoso and Saul Niguez scored early before Antoine Griezmann and Mario Mandzukic sealed a brilliant win.
Cristiano Ronaldo returned from suspension but couldn't help his team and failed to record a single shot on target during the 90 minutes.
"We didn't have a player who had a good game," Real coach Carlo Ancelotti said after.
Diego Simeone's side are undefeated in six meetings with Real Madrid since suffering a heartbreaking loss in last season's Champions League final.
"Everything went our way from the first minute and we didn't give Madrid a chance," said goal scorer Tiago. "Our coach again has been boosted because everything he said came to pass. He told us to find spaces to attack Madrid behind its defense and that's what happened."
The visitors were without several injured first-choice players in James Rodriguez, Sergio Ramos, Pepe, Luka Modric, while Marcelo was suspended.
But they still had enough star power with Ronaldo back from a two-match ban for kicking an opponent, Gareth Bale, Karim Benzema, and midfield pair Toni Kroos and Isco all in the side.
"We have to erase this match," said Madrid defender Dani Carvajal.
Since finishing 2014 with a Spanish record 22-win streak, Real have now been eliminated by Atletico from the Copa del Rey and been beaten for just a second time in the league this season.
Atletico overpowered Madrid in midfield - even after it lost playmaker Koke to a leg injury in the eighth minute - picking the visitors apart on the wings.
Atletico's first goal in the 12th minute started when right back Juanfran Torres broke down the flank to send in a cross that was flicked on to Mandzukic, who saw Tiago arriving in a second wave. Tiago drilled his strike through the hands of goalkeeper Iker Casillas, who could have done more to keep the ball out.
The goal left Madrid reeling and ignited the crowd as Atletico pressed for a second goal that it found through Niguez, Koke's replacement, four minutes later.
This time Madrid was overrun on the left as Siqueira dribbled to the byline before crossing for Niguez to stun both his team-mates and opponents with an acrobatic bicycle kick that sent the ball off the post and into the net.
Madrid needed 32 minutes to muster its first shot on goal - a harmless strike from Benzema - and Ancelotti sent on forward Jese Rodriguez for an ineffective Sami Khedira.
But Atletico went near a third goal on four occasions before Griezmann beat Raphael Varane to the far post where he tapped in Niguez's headed pass in the 67th.
Mandzukic then polished the result in the 89th when he headed in substitute Fernando Torres' cross.
Additional reporting from APReuse content