Real Sociedad beat Deportivo La Coruna 3-0 at home on Monday to send the visitors deeper into the La Liga relegation zone.
Deportivo are winless in the league this season and have taken just one point from their last five matches.
Things only got worse for Miguel Angel Lotina's side at the Estadio Anoeta as Sociedad controlled the match from the outset.
Joseba Llorente opened the scoring for the home side in the 17th minute after he headed home a pinpoint cross from Alberto De la Bella.
After Riki missed a great chance to level the scores, Antoine Griezmann put the hosts two goals up with another header, before Imanol Agirretxe sealed the win on 86 minutes after being set up by Jeffrey Sarpong.
It was a vital win for Sociedad, who returned to the top flight this season and have now moved three points clear of the relegation zone.