Manchester United's dwindling hopes of lifting a trophy this season are dangling by a thread after they produced an abject display to lose 2-0 at Olympiakos Piraeus in a Champions League last-16 first-leg.
That's the worst we've played in Europe, we didn't deserve to get anything
Alejandro Dominguez opened the scoring with a clever first-half flick and Arsenal loanee Joel Campbell added a sublime second goal to leave United facing a huge task to overturn the deficit in the return match at Old Trafford on March 19.
"That's the worst we've played in Europe, we didn't deserve to get anything," manager David Moyes told reporters. "I'm surprised, I didn't see that level of performance coming. I take responsibility, we have to play better. The players are hurting."
Defeat at the Georgios Karaiskakis Stadium represented yet another body blow in an inauspicious campaign for last season's English Premier League title winners.
United are out of the FA Cup and the League Cup and trail Premier League leaders Chelsea by 15 points with 11 games left to play.
It was the first time the Greeks had beaten United in five attempts.
Earlier, Borussia Dortmund's Robert Lewandowski scored twice in a clinical 4-2 win at Zenit St Petersburg.
The second leg on March 19 should now be a formality for last season's runners-up against opponents who qualified for the last-16 despite mustering only six points in the group stage and were clearly out of their depth in the knockout phase.
"We were incredibly active and aggressive, it's not easy to do that," Dortmund coach Juergen Klopp told reporters.
"This was close to an optimal performance. We pressed to great effect against a dangerous team."