Cristiano Ronaldo's bullet finish in the first-half was enough to settle a malicious Madrid derby.
A feisty affair with plenty of niggling battles saw Jose Antonio Reyes come off through injury to further deplete an attacking line already missing Sergio Aguero. The hosts lifted themselves for the second-half but couldn't find a way past Real Madrid 'keeper Iker Casillas.
The second-leg of the Copa del Rey derby began at a ferocious pace, both sides running at the defenses with Atletico brought to a stop on numerous occasions by the offside flag. However, the hosts started to settle into the game depriving Jose Mourinho's men of the ball in dangerous territory.
The early tempo evaporated as Real Madrid started to dominate proceedings, at least in terms of possession, but their eagerness to retain the ball on the ground almost proved costly with 14 minutes on the clock.
A back-pass to Casillas was quickly closed down by Reyes and the Blancos goalkeeper blasted his clearance off the winger, but was fortunate to see the ball spin away from goal and the defense eventually recovered.
Real Madrid got the all important away goal in the 23rd minute as Xabi Alonso played a delightful chipped pass wide to Sergio Ramos who was in space. The right-back looked up and hit a low cross into the area which dropped kindly to Cristiano Ronaldo and the lone striker on the night made no mistake with a powerful effort to make it 1-0.
Things got immediately worse for Atleti as they were forced to replace Reyes, the winger unable to run-off a knock and Diego Costa came on.
Atletico came a whisker away from an equalizer just before the half-hour mark. Diego Costa skipped round Arbeloa with ease but drilled his cross right through the area with Diego Forlan unable to stretch to turn it in.
Quick thinking by Forlan then found Diego Costa's bending run to send the forward clean on goal but the official's flag quickly went up, and wrongly in this case for Atleti.
A moment of magic from Ronaldo to find Angel Di Maria with a backheel in the box should have resulted in a second for los Blancos, but the winger tried to turn inside Juan Valera and the right-back got a block in to allow the ball to run to David De Gea.
The half-time team talk had clearly lifted the Rojiblancos when they returned to the field, Fran Merida, Tiago and Forlan all creating shooting chances.
Cristiano Ronaldo was next to see yellow from the referee's pocket, the Portuguese forward not waiting for the whistle to take a free-kick and the crowd went wild sounding their appreciation for what was a harsh decision.
Atletico refused to give up the chase but were simply becoming frustrated. The home team were however fortunate to see Marcelo have a goal chalked off for offside, the little Brazilian winger level when the ball was played through.
Real Madrid made their changes as the game ticked away and Jose Mourinho's men proceeded to play keep-ball to run down the time on Atletico's cup hope.
Real Madrid will now play Sevilla in the semi-final of the tournament.
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