Sevilla will contest the Europa League final after Stephane Mbia scored deep into stoppage time to take them through on away goals against Valencia.
Los Che trailed 2-0 from last week's first leg, but goals from Sofiane Feghouli, Jonas and Jeremy Mathieu looked to have turned it around at home against their La Liga rivals.
However, with the home side looking odds-on for a place in the final, midfielder Mbia struck to take the visitors into the showpiece fixture where they will meet Benfica.
It started well for the Mestalla outfit, and Feghouli put his side firmly back in the tie on 14 minutes when he drove at the heart of the Sevilla defence from a wide area before finding the top corner inside the area.
The Algerian winger nearly evened things up six minutes later but Beto was on hand to make a good save after some nice build-up between Feghouli and Jonas.
Brazilian midfielder Jonas levelled the tie up on aggregate when he powered a header beyond Beto, despite the goalkeeper palming it onto the crossbar before it eventually rolled over the line.
Jose Antonio Reyes nearly gave the visitors the advantage once more, but the former Arsenal forward was denied by Valencia goalkeeper Diego Alves.
After the break, the game was devoid of any real goalmouth activity until Mathieu popped up with 20 minutes to swing the tie in the home side's favour.
The Frenchman reacted quickest inside the penalty area to power home, and Juan Antonio Pizzi's side looked as though they were heading for the final until Mbia struck in stoppage time with a priceless away goal for the visitors.