Manchester United's Under-19s lost out to Group A leaders Real Sociedad in the UEFA Youth League after Alvaro Odriozola's early goal proved decisive.
The Reds have three points from three matches and face an uphill battle to qualify for the knockout stages of the inaugural competition with a positive result probably required in San Sebastian next time out. Ben Pearson's injury-time red card only added to the frustration.
Real Sociedad were comfortable on the ball and sliced through the defence to open the scoring in less than four minutes. Jon Bautista drew Joel Castro Pereira and teed up Odriozola for a simple side-footed finish to hand the Reds the worst possible start.
Nicky Butt's side struggled to make an impression, although Josh Harrop did have a shot saved by Igor Marcellan, and only a fine stop by Joel Castro Pereira denied Odriozola a second goal from a one-on-one situation.
A rare mistake by Pearson was pounced upon by Bautista but, again, Joel Castro Pereira came to the rescue after advancing well from his goal. The United keeper's opposite number Marcellan was much less involved but did push an Andreas Pereira free-kick behind for a corner.
Following yellow cards for Louis Rowley and Roberto Olabe, Sam Byrne cut inside from the left but fired over the bar from the edge of the box. The hosts were quick out of the traps after the restart and should have equalised on 48 minutes. Byrne released Harrop and, when the flag stayed down, the midfielder had time to pick his spot but could only place his finish wide.