Fernando Llorente fired Athletic Bilbao into the Europa League final with an 88th-minute strike as his side overturned a first-leg deficit to see off Sporting Lisbon 3-1 at the Estadio San Mames.
Marcelo Bielsa's men, who accounted for Manchester United early in the competition, looked set to take the tie into extra-time after goals from Markel Susaete and Gomez Ibai sandwiched a strike from Rene van Wolfswinkel.
But with the score at 2-1 to Athletic on the night and 3-3 on aggregate, Llorente lashed a right-foot shot into the corner of the net from an Ibai cross to seal the home side's passage into the final where they will meet fellow Spaniards Atletico Madrid.
Adrian's brilliant second-half strike sent Atletico into the all-Spanish final with a 1-0 victory at Valencia.
The forward thumped a glorious angled shot into the top corner in the 60th minute to end Valencia's hopes of a comeback in the second leg of the last-four clash.
The hosts, 4-2 down from the first leg, did everything but score in a one-sided first half as their opponents lived very dangerously, but Adrian taught them a lesson in clinical finishing.