Substitute Imanol Agirretxe netted a dramatic stoppage-time winner to give the hosts a surprise 3-2 victory over the Catalan giants.
Below, Sports Mole analyses whether the result was an accurate reflection of the 90 minutes.
On target: 6
On target: 3
Was the result fair?
Don't let the fact that Barcelona claimed 68% of the possession fool you. Sociedad put in a spirited performance to grind out this victory, especially when you consider that they had to come from two goals down to secure it.
Real Sociedad's performance
They looked a little overwhelmed in the early stages and were vulnerable to Barcelona's long balls and pacey strikers, but the second half was a different story. Sociedad controlled the game after the break and did all of the pressing, never letting up until they had gotten the job done.
Barcelona looked like their old selves for much of the first half, never wasting an opportunity to punish Sociedad for the slightest of mistakes. They deserved their half-time lead of 2-1 but Gerard Pique's sending-off rattled them, allowing the hosts to control and totally dominate the second period.
Sports Mole's man of the match
Gonzalo Castro: Sociedad's two-goal hero is the obvious choice. Castro was essentially the home side's answer to Messi, giving them a genuine goal threat up front. There was an element of fortune about his second goal, but let's take nothing away from him on an evening where he shone.
This award goes to Pique for his first yellow card offence. Shakira's other half displayed a lack of professionalism when he picked up a needless booking for dissent in the first half, an incident that would cost his team dear later on.
Alberto Undiano had a tough job on his hands overseeing this fiery contest, but he more than held his own. Seven yellow cards were shown in total and they were all the right call.
Real Sociedad: Real Sociedad pay a visit to Celta Vigo in their next league outing.
Barcelona: Barcelona are in Copa del Rey action in their next game, travelling to Malaga for the second leg of their quarter-final tie.