Karim Benzema scored a hat-trick in a dominant 4-0 win over Barcelona to send Real Madrid into the Copa del Rey final with a 4-1 aggregate victory.
Barcelona, who carried a one-goal lead into the second leg, were comfortable for the majority of the first half until Vinicius Jr scored his first goal at the Camp Nou to level the tie on the stroke of half time.
Benzema completed the Real Madrid turnaround in the opening stages of the second half, caressing the ball into the bottom corner.
In the 58th minute, the Frenchman kept his composure from the penalty spot to give Real Madrid a two-goal aggregate lead, and he wrapped up his first El Clasico hat-trick in the 80th minute to send Los Blancos into their first Copa del Rey final since 2014.
Real Madrid still have the chance to win two trophies this season, while Barcelona's hopes of winning a double are now over.
Barcelona took a slender advantage into the second leg after an Eder Militao own goal guided them to a 1-0 victory at the Santiago Bernabeu.
The hosts began the contest on the front foot, and they carved out a promising opportunity in the opening 15 minutes when a dangerous Alejandro Balde cross found an unmarked Raphinha, who could only guide his tame header straight at Thibaut Courtois.
Despite carrying the greater threat in the first period, Barcelona were finding it tough to create clear-cut chances, but their opponents were also finding little joy in the final third.
Los Blancos showed signs of encouragement just after the half-hour mark as Toni Kroos clipped the ball towards the back post for Benzema to force Marc-Andre ter Stegen into a routine stop.
As the contest entered first-half stoppage time, the second leg burst into life as Real Madrid survived a scare at one end of the pitch when Courtois made a superb save to deny Robert Lewandowski.
Within 20 seconds of Courtois' crucial stop, Real Madrid had levelled the tie through Vinicius Jr, who rounded off a clinical counter-attack with a toe-poke that squirmed over the goalline.
Vinicius's strike appeared to cross the line before Benzema got a touch, but the Frenchman had a goal to celebrate within five minutes of the restart, sweeping the ball home from the edge of the box.
Real Madrid were given the opportunity to establish a two-goal aggregate lead when Kessie clumsily brought Vinicius Jr down in the penalty box.
A calm and composed Benzema assumed responsibility, sending Ter Stegen the wrong way to put Los Blancos in complete control.
Barcelona attempted to find a way back into the tie, but any lingering hopes of a final appearance were vanquished in the 80th minute when Benzema coolly slotted the ball past Ter Stegen to register back-to-back hat-tricks.
Real Madrid will go on to face Osasuna in the Copa del Rey final, while Barcelona will turn their attention to league matters for the remainder of the season.