Mikel Oyarzabal and Takefusa Kubo struck for Real Sociedad in a 2-0 win over Getafe on Saturday to help the Basque side tighten their grip on fourth place in LaLiga.
Amid a run of inconsistent form after a strong start to the season, La Real suffered Europa League elimination and allowed Real Betis and Villarreal to close in behind them in the hunt for Champions League football.
Atletico Madrid, third, overtook Real Sociedad in March after the Basque side dropped points in a draw with lowly Cadiz.
With this solid victory over Getafe, Real Sociedad moved six points clear of Real Betis, fifth, who face Cadiz on Sunday.
After an even first half Oyarzabal won the chance to put La Real ahead from the penalty spot when Dakonam Djene felled him in the area.
However, the striker, usually lethal from the spot, took a weak spot-kick which David Soria saved easily down to his right after 44 minutes.
Oyarzabal did not have to wait long to make amends, though, heading home in first-half stoppage time from close range after Soria could only parry Brais Mendez's shot.
On the hour mark, Kubo doubled Real Sociedad's lead after a fine team move, with Mikel Merino sweeping the ball across goal into his path.
Ander Barrenetxea might have scored the third but could not connect with a dangerous cross, as Imanol Alguacil's side kept Getafe, 14th, where they wanted them.
Earlier Athletic Bilbao bounced back from their Copa del Rey semifinal defeat by Osasuna this week with a 2-1 win over Espanyol.
Brothers Inaki and Nico Williams scored the goals, with Sergi Darder netting one late on for the struggling hosts, 18th, in their first game under new coach Luis Garcia.
Espanyol suffered their fifth consecutive defeat in the Spanish top flight.
Barcelona winger Ez Abde, on loan at Osasuna, shone and struck twice for the cup finalists in a 2-1 win over bottom-of-the-table Elche.
Later Saturday Real Madrid, second, hope to cut the gap on leaders Barcelona to nine points when they host Villarreal, sixth.