Ten-man Benfica held Juventus to a goalless draw to progress to the UEFA Europa League final for a second consecutive year.
The Portuguese champions carried a 2-1 lead into the game in Turin and held on with Juve's best chance coming late in the first half. Benfica defender Luisao made a goal-line clearance from Arturo Vidal's header with the visiting goalkeeper Jan Oblak already beaten.
The Portuguese champions had midfielder Enzo Perez sent off for a double booking with 23 minutes remaining but defended deeply to hold on.
Stephane Mbia headed home a dramatic stoppage-time winner to send Sevilla through to the Europa League final on away goals at the expense of unlucky Valencia, who were denied another stunning comeback in heartbreaking fashion.
Sevilla led 2-0 from the first leg but looked on their way out as Valencia scored three times at the Mestalla through Sofiane Feghouli, an Antonio Beto own goal and Jeremy Mathieu to take a deserved 3-2 lead on aggregate.
However, just as it looked as though Juan Antonio Pizzi's side would record another remarkable recovery having overturned a 3-0 first-leg deficit to beat Basel 5-3 in the quarter-finals, on-loan QPR midfielder Mbia rose to power home a header four minutes into injury time for the decisive away goal in a 3-1 defeat.
There was not enough time for crushed Valencia to respond after that as 2006 and 2007 UEFA Cup winners Sevilla held on for a final showdown against Benfica.
Benfica and Sevilla will meet in the final on 14 May at the Juventus stadium.