Real Sociedad were pegged back to draw after Antoine Griezmann twice gave them the lead over Valladolid at the Estadio Jose Zorrilla.
The 21-year-old struck in the 37th and 57th minutes but Patrick Ebert levelled from long range just before half-time and then set up Oscar for the second equaliser.
Sociedad could still have won it deep into stoppage time but Jose Angel's shot from his own half was tipped over.
Gonzalo Castro's shot wide for the visitors was an isolated early threat, and Asier Illarramendi's free-kick on the quarter-hour was also off target.
Ebert's powerful dead-ball effort at the other end drew the night's first save from Sociedad keeper Enaut Zubikarai, who also gathered Javi Guerra's close-range header and another Ebert drive.
But it was Sociedad who made the breakthrough eight minutes before half-time when Castro's corner found its way to Griezmann, who finished from close range.
Zubikarai made a fantastic save from Guerra but was helpless when the impressive Ebert let fly from 25 yards to equalise two minutes before the break.
Griezmann fired against the bar early in the second half after Carlos Vela's pass put him in a good scoring position.
But the Frenchman got his second goal when he once again took Vela's pass in his stride and scoring with a superb shot from 20 yards.
Valladolid's Victor Perez fired over after Zubikarai punched clear Mikel Balenziaga's cross, but the equaliser came with 15 minutes remaining.
Ebert was again central to the goal, crossing from the right for Oscar to head home impressively.
Griezmann was forced off by injury with 10 minutes remaining and Ruben Pardo's pair of long-range efforts were in vain.
Sociedad almost won the game in dramatic style when Angel launched his ambitious effort in the last seconds, but home keeper Dani Hernandez stayed alert to save.