Fernando Torres struck his first goals since returning to Atletico Madrid, firing a brace to seal a 4-2 Copa del Rey aggregate win over Real Madrid.
Atletico led 2-0 from the first leg and Torres stunned the Bernabeu, smashing in left-footed after 49 seconds.
Sergio Ramos's header levelled but, in the first minute of the second half, Torres beat Pepe to slide in a second.
Holders Real needed three goals to win after Cristiano Ronaldo's header but Atleti held on to reach the last eight.
Their success - a first domestic cup defeat for Carlo Ancelotti since becoming Real Madrid manager - will likely yield a last-four meeting with Barcelona, who lead Elche 5-0 after their first leg.
Los Rojiblancos can also boast being five games unbeaten against their city rivals this season and that record looked safe inside a minute.
Cristiano Ronaldo paraded his Ballon d'Or award moments before kick-off but Fernando Torres scored quickly to change the mood
Soon after Ronaldo stopped parading his Fifa Ballon d'Or award moments before kick-off, Torres plundered the opener, sweeping into the top corner from 10 yards with a first-time shot following Antoine Griezmann's cross.
Torres, who left Atleti in 2007, had never scored at the Bernabeu with his boyhood club but, in for the unwell Mario Mandzukic, he left Real needing four goals to progress.
Ramos netted a last-minute leveller which spurred Real on to a 4-1 extra-time win over Atletico in last season's Champions League final and he was in the right place when goalkeeper Jan Oblak - making just his fifth appearance - flapped at a set-piece delivery.
Play media
Jump media player
Media player help
Out of media player. Press enter to return or tab to continue.
Fernando Torres: Huge welcome on return to Atletico Madrid
Swarms of white shirts peppered the visitors' area and Ronaldo's goal-bound strike was only kept out by Mario Suarez on the goal-line as Real dominated with 76% of possession in the opening half.
But Diego Simeone's side only had 27% of the ball in the first leg and they again demonstrated the resilience he has instilled in them since taking over in January 2011.
The Argentine has delivered successive league finishes of fifth, third and first along with Europa League success in 2012 and a Copa del Rey triumph in 2013.
In Europa League, Champions League and Copa del Rey fixtures, he now has 16 successes from 17 two-legged ties and Torres's second came at the perfect time, killing Real's second-half hope.
He again collected a Griezmann pass before wrong-footing Pepe to fire under Keylor Navas.
Ronaldo - voted the greatest player in Portugal's history on Wednesday - headed in from six yards to reduce the arrears on 54 minutes before Torres was substituted to jeers from the home fans.
Karim Benzema could not turn their frustration to hope when he fired over from four yards as the home challenge petered out.
The Real Madrid team bus arrived amid passionate and colourful scenes at the Santiago Bernabeu
Torres finished with a first-time volley and saluted visiting fans sat high in the Bernabeu stands
Sergio Ramos scored his fifth club goal of the season as Real mounted heavy pressure following the opening goal
Fernando Torres was mobbed by Atletico's players when he netted a second less than a minute after the interval
Atletico led 2-0 from the first leg and Torres stunned the Bernabeu, smashing in left-footed after 49 seconds.
Sergio Ramos's header levelled but, in the first minute of the second half, Torres beat Pepe to slide in a second.
Holders Real needed three goals to win after Cristiano Ronaldo's header but Atleti held on to reach the last eight.
Their success - a first domestic cup defeat for Carlo Ancelotti since becoming Real Madrid manager - will likely yield a last-four meeting with Barcelona, who lead Elche 5-0 after their first leg.
Los Rojiblancos can also boast being five games unbeaten against their city rivals this season and that record looked safe inside a minute.
Cristiano Ronaldo paraded his Ballon d'Or award moments before kick-off but Fernando Torres scored quickly to change the mood
Soon after Ronaldo stopped parading his Fifa Ballon d'Or award moments before kick-off, Torres plundered the opener, sweeping into the top corner from 10 yards with a first-time shot following Antoine Griezmann's cross.
Torres, who left Atleti in 2007, had never scored at the Bernabeu with his boyhood club but, in for the unwell Mario Mandzukic, he left Real needing four goals to progress.
Ramos netted a last-minute leveller which spurred Real on to a 4-1 extra-time win over Atletico in last season's Champions League final and he was in the right place when goalkeeper Jan Oblak - making just his fifth appearance - flapped at a set-piece delivery.
Play media
Jump media player
Media player help
Out of media player. Press enter to return or tab to continue.
Fernando Torres: Huge welcome on return to Atletico Madrid
Swarms of white shirts peppered the visitors' area and Ronaldo's goal-bound strike was only kept out by Mario Suarez on the goal-line as Real dominated with 76% of possession in the opening half.
But Diego Simeone's side only had 27% of the ball in the first leg and they again demonstrated the resilience he has instilled in them since taking over in January 2011.
The Argentine has delivered successive league finishes of fifth, third and first along with Europa League success in 2012 and a Copa del Rey triumph in 2013.
In Europa League, Champions League and Copa del Rey fixtures, he now has 16 successes from 17 two-legged ties and Torres's second came at the perfect time, killing Real's second-half hope.
He again collected a Griezmann pass before wrong-footing Pepe to fire under Keylor Navas.
Ronaldo - voted the greatest player in Portugal's history on Wednesday - headed in from six yards to reduce the arrears on 54 minutes before Torres was substituted to jeers from the home fans.
Karim Benzema could not turn their frustration to hope when he fired over from four yards as the home challenge petered out.
The Real Madrid team bus arrived amid passionate and colourful scenes at the Santiago Bernabeu
Torres finished with a first-time volley and saluted visiting fans sat high in the Bernabeu stands
Sergio Ramos scored his fifth club goal of the season as Real mounted heavy pressure following the opening goal
Fernando Torres was mobbed by Atletico's players when he netted a second less than a minute after the interval
