The forward thumped a glorious angled shot into the top corner in the 60th minute to end their Spanish rivals faint hopes of a comeback.
The hosts, 4-2 down from the first leg, did everything but score in a one-sided first-half as their opponents lived dangerously, but Adrian taught them a lesson in clinical finishing.
Atletico lost captain Thiago to a needless red card late on when he was dismissed following a mass confrontation and the former Chelsea midfielder will now miss the final.
Valencia, with work to do to get back in the tie, were quickly on top but struggled to break down a resolute opposing back four.
Indeed, that was the theme for much of the night and despite having a man extra for the remaining 11 minutes, Atletico survived.
VALENCIA: Diego Alves, Barragan, Rami, Ricardo Costa, Jordi Alba, Albelda, Parejo (Tino Costa 68), Feghouli, Jonas (Aduriz 57), Canales (Mathieu 58), Soldado.
ATLETICO MADRID: Courtois, Juanfran, Godin, Miranda, Filipe Luis, Mario Suarez (Gabi 46), Tiago, Turan (Salvio 74), Adrian, Diego (Koke 84), Falcao.
Referee: Damir Skomina (Slovenia).