Fernando Llorente struck late as Athletic Bilbao set up a Europa League final with Spanish rivals Atletico Madrid.
After their semi-final first leg at Sporting Lisbon finished 2-1 to the Portuguese side, Bilbao made a brilliant start when Markel Susaeta struck the first goal of the second leg after 17 minutes.
Then in two quick-fire minutes, Ricky van Wolfswinkel edged Sporting back in front, before Gomez Ibai netted another for Bilbao moments before the break.
With the score level at 3-3 on aggregate, the game looked to be heading to extra time when Bilbao's talismanic forward Llorente made his mark on the tie, converting from close range two minutes from time to ensure Bilbao progressed 4-3 on aggregate.
Things were much simpler for Atletico, who did most of the hard work in their first leg with Valencia last week, which they won 4-2.
A wonderful strike from Adrian put the gloss on a superb 5-2 aggregate win though, the forward thumping a glorious angled shot into the top corner in the 60th minute to end Valencia's hopes of a comeback.
Atletico lost captain Thiago to a needless red card late on when he was dismissed following a mass confrontation and he will now miss the final on May 9.