Second-half goals from Antoine Griezmann and Carlos Vela were enough to hand Real Sociedad their first win in the Basque derby for two-and-a-half years as they triumphed 2-0 over Athletic Bilbao in a scrappy game at Anoeta.
Griezmann had looked the most likely to break the deadlock throughout and after having two fierce efforts well saved by Gorka Iraizoz in the first-half, he finally got his goal on 62 minutes when his shot took a slight deflection on its way past the helpless goalkeeper.
And any hope of a comeback from the visitors was extinguished 10 minutes later when Fernando Amorebieta saw a second yellow card for handling Xabi Prieto's shot inside the area and Carlos Vela converted the resulting penalty with ease.
Athletic had won both meetings between the sides last season, but Marcelo Bielsa's side have looked a shadow of the team that stormed to two cup finals last term so far this campaign and so it proved again as Sociedad made the most of a tepid performance by the visitors.
Griezmann was first to threaten as his powerful free-kick was punched away by Iraizoz on 10 minutes and the 21-year-old was then presented with the best chance of the first half eight minutes before the break when David Zurutuza found him inside the area, but again Iraizoz was equal to his attempt as the keeper dived to his right to turn the ball behind.
Asier Illarramendi was next to force the Bilbao number one into a flying save from fully 35 yards moments later, but the visitors failed to reorganise at the break and eventually Sociedad's pressure told after the hour mark as Griezmann latched onto Imanol Agirretxe's pass to pull his shot into the bottom corner.
And the game was put firmly beyond Athletic's reach 18 minutes from time when after Iraizoz had produced another brilliant save to deny Griezmann, the rebound fell to Prieto and his goalbound effort was handled by Amorebieta.
The defender was shown his second yellow card, meaning he was dismissed for an 11th time in the Primera Division. Vela stepped up and rolled the penalty home.
A final save from Iraizoz denied Prieto a third goal for the home side in the final minute but the goalkeeper's heroics were to no avail as Sociedad saw the game out to continue their 100% record at home so far this season.