Two goals from Markel Susaeta guided Athletic Bilbao to their second victory over Basque rivals Real Sociedad this season and took them back into the top four in La Liga.
The hosts had by far the better of the opening period and deservedly went ahead when Susaeta collected Andoni Iraola's pass to fire past Claudio Bravo. Susaeta also hit the bar and Bravo made a terrific triple save just before the break to keep the scoreline down, but Real Sociedad should have been level within minutes of the restart.
Carlos Vela appealed that his effort went over the goal-line before Gorka Iraizoz pulled it into his grasp, however the goal was not given and, despite being under pressure, Athletic sealed all three points when Susaeta curled in a wonderful free-kick with ten minutes remaining.
Athletic's 2-1 win in San Sebastian in week six proved to be the springboard for what has so far been a very successful season and they looked in complete control against their neighbours once again in the first half.
The opening goal arrived in the 24th minute and it was a lesson in how Marcelo Bielsa has changed the footballing philosophy of his side as Susaeta, Ander Herrera and Iraola exchanged passes before the latter slid Susaeta through for a clinical right-footed finish.
The Athletic midfielder almost had his second 14 minutes later as his free-kick from fully 30 yards came crashing back off the crossbar and Bravo then came to Sociedad's rescue as he repelled efforts from Fernando Llorente, Iker Muniain and Susaeta within seconds of one another to allow the visitors to go in only one down at the break.
However it was a different story in the second half as Sociedad showed much greater attacking intent and Athletic tired. Vela was unfortunate as after a goalmouth scramble saw his shot near the line on 47 minutes, but it was adjudged to not be a goal.
Liassine Cadamuro also had a goal ruled out for offside and Iraizoz was forced into a smart double stop from Imanol Agirretxe and Antoine Griezmann, but it was Athletic who struck the all-important second goal against the run of play. Muniain had been chopped down by Mikel Gonzalez, and Susaeta sent another sumptuous free-kick over the wall and this time into Bravo's top left-hand corner.