Valencia stunned Barcelona 3-2 at the Mestalla to reach the King's Cup final 4-3 on aggregate on Thursday.
Barca, who had scrambled an injury-time equaliser to draw 1-1 in the first leg, were hit by a Ruben Baraja piledriver and a breakaway goal from Juan Mata before the break in an intense encounter they dominated throughout.
Substitute Thierry Henry pulled one back for Barca in the second half only for Mata to bag his second almost immediately and although a late Samuel Eto'o goal set up a grandstand finish, it was to no avail.
The victory relieves some of the pressure on Valencia coach Ronald Koeman who has seen his side drop out of Europe and the league title race since he replaced Quique Sanchez Flores in November.
Valencia will meet Getafe on April 16, with a place in next season's UEFA Cup up for grabs, after Michael Laudrup's side booked a second consecutive appearance in the final with a 4-2 aggregate victory over Racing Santander on Wednesday.