Unai Emery's side went into the second leg at the Estadio Municipal de Anduva with a two-goal lead from the first leg, and they went one better this evening to ease into the last four, running out 3-0 victors.
The opening goal on the night took less than 10 minutes to arrive as Ion Velez brought down Sebastian Cristoforo in the penalty area, allowing Vicente Iborra to step up and place the spot kick into the bottom corner.
It was the visitors who continued to look most likely to add another, with Sergio Escudero and Yevhen Konoplyanka having shooting opportunities in quick succession as they went in search of a goal that would well and truly kill the tie off.
The hosts did begin to ask more questions of the Sevilla defence in the early stages of the second half as both Prats and Alex Garcia got shots away, but it was Sevilla who continued to have the better sights of goal through the likes of Juan Munoz, Iborra and Fernando Llorente.
Their second goal finally arrived with 20 minutes of the match remaining, and it was Munoz who killed things off with a close-range finish from Vitolo's ball.
Mirandes came within inches of a late consolation goal when Nestor Salinas connected with Garcia's cross to nod goalwards, only to see his header come back off the left upright.