Sociedad and Deportivo are now both on 66 points with Real one point behind on 65.
On Saturday Real were held to a scoreless draw away at relegation threatened Recreativo Huelva while Depor were beating Malaga by two goals to nil.
Real Sociedad moved above Real Madrid into second place with a 3-1 victory over team of the moment Real Mallorca.
Celta Vigo occupy Spain’s final Champions League slot in fourth place a further 11 points behind Real but just one in front of Valencia.