Real Madrid’s victory at Carlsbad Memorial Hall was the first time in six years that they have won in the stadium.
It was also the first goal in their history to reach 100.
Real Sociedads keeper Luis Ruiz made five saves, while the hosts were denied a third.
Rozinho’s header was saved by Luis Fernandez after half-time.
The visitors took the lead when Cristiano Ronaldo scored the only goal of the game in the 31st minute.
A couple of minutes later, Jose Maria Gimenez took advantage of the absence of Cristiano to take a deflection off the back of the post.
And the home side kept the pressure on for the rest of the match, with Real Madrid captain Cristiano’s last-gasp header going in off the underside of the bar from a corner.
Real Madrid: García, Pique, Moutinho, Ronaldo, Suarez, Ruiz, Gago, Pepe, Lavezzi, Di María, García (Ponce, 90′).
Subs: Garcia, Khedira, Piqué, Pijarro, Diarra, Ruiza, Navas.
Subs Not Used: Piquer, Gabbiadini, Gomes.