In-form Dembele’s second half solitary strike proved crucial for Barcelona at the Spotify Camp Nou as they book their place in the Copa del Rey semi-final.
Real Sociedad were only hanging in by a thread as Barca stamped their authority from the outset but failed to get the breakthrough in the first 45 minutes.
Brais Mendez was dismissed in the 40th minute following his high tackle on Sergio Busquets — his initial yellow card was upgraded to a straight red after VAR check.
The red card obviously handed the hosts the numerical advantage with the Catalan giants taking the lead immediately after the restart.
Ousmane Dembele finally scored the opener after the resumption when he latched onto a through ball from Jules Kounde and powerfully lashed a low ball past Alex Remiro.
Societal came close to getting the equalizer when Sorloth missed the target a couple of yards while Ter Stegen sensationally denied Navarro in a one-on-one situation.
The result has sent Barcelona through to the semifinals of the competition as the Blaugrana look to add another trophy to their recent Supercopa de Espana success.