Two goals from Cristiano Ronaldo and a third from 19-year-old French defender, Raphael Varane, were enough to see Real Madrid humiliate arch-rivals, Barcelona in their home.
Barcelona had earlier travelled to Madrid for the first leg of the semi final of the Copa del Rey where they scored first and drew 1-1; setting the pace for the return leg.
The return leg at the Camp Nou on Tuesday night was a classic as both sides played entertaining football with Madrid clearly the more purposeful side.
Ronaldo's first goal of the night was a penalty after he was brought down in the box by Pique following a brilliant dribble of the defender. The Portuguese sent the goalkeeper the wrong way to slot the ball home.
Madrid showed they were determined to humble their host in the second half as a composed defensive display and counter-attack again gave Ronaldo the second.
Angel Di Maria had a one on one with Barcelona Captain, Puyol, and sublimely dribbled past the defender. His shot was saved by the Barcelona keeper of the night, Pinto, into the path of Ronaldo who calmly executed a fine finish.
Raphael Varane scored a third with a header to give Madrid a third goal.
Barcelona stars, Messi, Xavi, Iniesta, and others could do nothing to unlock the Madrid defence.
A consolation goal by Barcelona towards the end of the second half could not stop their visitors from qualifying for the final with a 3-1 win on the night and a 4-2 aggregate victory.
Both sides will meet in another El-Classico at the weekend in the Spanish La Liga. However, that is not expected to be a very tough match as Real Madrid have virtually given up on the league title with their rivals leading by about 17 points.