Erik ten Hag saw Manchester United's recent revival end with a whimper in the Europa League as Real Sociedad ground out a 1-0 win at Old Trafford.
A controversial penalty, given after a ball bounced off Lisandro Martinez's thigh into his arm, was coolly dispatched by Brais Mendez to condemn United to their first defeat in five matches.
United failed to muster up an adequate response following Mendez's 58th minute opener and managed just three shots on target to cap a disappointing night.
