Manchester United were held to a 1-1 draw in San Sebastian, with Joshua Zirkzee's second half opener cancelled out by Real Sociedad, with the sides now heading back to Old Trafford level.
Despite being the better side, United went in level at the break, with neither team able to break the deadlock in a tense opening half.
But within 12 minutes of the second period, Zirkzee had United in front at last, finishing low and hard down the middle of the goal after a brilliant cutback from Alejandro Garnacho.
However the lead would not last long, with Mikel Oyarzabal levelling from the spot following a handball from captain Bruno Fernandes.