The Red Devils thrashed the La Liga side to gain an unassailable lead in aggregate.
The Spanish club didn’t have the home ground advantage and the game took place in the neutral venue, Turin due to travel restrictions.
Despite Marcus Rashford’s costly miss early on in the game, Bruno Fernandes opened the account before the half-hour mark, taking advantage of an erratic collision between Sociedad defenders and goalkeeper Alex Remiro.
Following the goal, the Spaniards imposed more threat due to their attacking football but were let down by the not-so-clinical finishing in the attacking third.
United started the second half with a bang as Fernandes completed his brace in the 57th minutes before Rashford made amends for his earlier mistake by finding the back of the nets.
Daniel James wound up the game by scoring United’s fourth goal although he had a goal ruled out moments earlier due to offside.
Ole Gunnar Solskjaer‘s men picked up a crucial away win and have taken a big step towards the last 16.
Sociedad found United’s attack overwhelming although they played attractive football for fewer parts of the game.
The victory would also be a sigh of relief for the Red Devils following their clumsy run in the Premier League of late.
United, who trail crosstown rivals Manchester City by 10 points, will play Newcastle United this weekend.