The hosts had an early scare when Salomon Rondon’s header was well-saved by Odysseas Vlachodimos, but in the next attack, they took the lead themselves.
Lucien Agouma threaded through Akor Adams, who calmly slotted past Aaron Escandell.
Adams then turned provider for Djibril Sow to find the bottom corner as Sevilla doubled their advantage midway through the first half.
Adams could have scored again right before half-time when he sent his half-volley over in a promising position, but Sevilla remained in control regardless.
They did not have to wait long into the second half to net their third, either, as Adams grabbed his second assist by flicking on for Batista Mendy, who produced some lovely skill himself before scoring.
Sevilla’s number nine was at the heart of everything, and could have had a hat-trick as his diving header from a corner was tipped over by Escandell before the goalkeeper denied him again from a wide angle.
Things went from bad to worse for Oviedo in the latter stages as their appalling disciplinary record continued.
Having had two players sent off last week against RCD Mallorca, they picked up their seventh red card of the season when David Carmo made two needless challenges in the space of a minute to earn two yellows.
Chidera Ejuke then put the icing on the cake for Sevilla with a brilliant solo goal just before the start of stoppage time.
The visitors are now winless in nine league matches as they stay firmly in the relegation zone, while Sevilla break back into the top half with just a second victory in eight LaLiga games.
Flashscore Man of the Match: Akor Adams (Sevilla)