The host was unable to find the breakthrough in the first half despite dominating, but was handed an advantage when Brais Mendez was sent off in the 40th minute.

Ousmane Dembele gave the Blaugrana the lead early in the second half after being played through by Jules Kounde, finishing powerfully past Alex Remiro.

The contest between LaLiga's first and third-placed teams was rarely as close as the scoreline suggested until a late push from Sociedad, and Xavi's men march on looking to add another trophy to their recent Supercopa de Espana success.

Barca started brightly and had the ball in the net in the 11th minute, but Robert Lewandowski's goal-bound strike deflected off the offside Frenkie de Jong on its way in.

The dangerous Dembele threatened shortly after when a determined run ended with a curled effort just wide of the left-hand post, while Takefusa Kubo struck the crossbar just before the half-hour with the visitor's first attempt.

There were borderline ironic cheers before half-time from the home fans as referee Gil Manzano, who sent off Lewandowski earlier in the season, handed a red card to La Real's Mendez when a VAR review showed the midfielder had caught Sergio Busquets on the ankle with his studs.

Dembele opened the scoring in the 52nd minute when he raced onto a pass down the right channel from Kounde, before firing his shot past Remiro at his near post.

La Real should have been level on the hour when Alexander Sorloth somehow turned Kubo's cross over the bar from close range, while Gavi hit the woodwork at the other end. 

One goal was enough to seal Barca's passage to the final four, though, thanks to late Marc-Andre ter Stegen saves to keep out Roberto Navarro from a one-on-one and then Jon Ander Olasagasti's powerful drive.