David Moyes admitted he was stunned by the inept display of his players as Manchester United were left on the brink of an early Champions League exit by Greek side Olympiacos.
Goals from Alejandro Dominguez and Arsenal loanee Joel Campbell gave Olympiacos a 2-0 lead at the halfway point of their Champions League last-16 tie against United.
Given that Moyes' men are 11 points adrift of the top four, winning the Champions League was seen as their best way back into the competition.
But after such a woeful performance in Athens, the odds are firmly stacked against the reigning Barclays Premier League champions making the quarter-finals.
"That's the worst we have played in Europe," the United manager said.
"It was a really poor performance. We never really got going from the start and we didn't deserve anything because of the way we played.
"We never really got to grips with things and to a man you could hardly pick anybody out. We just didn't perform.
"We came into the game in good form and a good mindset but it just didn't show. I am just surprised. I didn't see that level of performance coming. I just didn't see it."
Olympiacos goalkeeper Roberto did not have a save to make all match as Wayne Rooney and his team-mates failed to live up to their pre-match bravado.
Other than a wayward effort from Robin van Persie, United did not look like scoring at all.
Tom Cleverley and Michael Carrick failed to take any hold of the game in midfield and Chris Smalling had a very poor game at right-back.
It was United's manager who took the blame for the manner of the defeat, though.
"I take responsibility," Moyes said
"It is my time and I will always front it up. We didn't play well. We have to play better."
Although the raucous home support in the sold-out Karaisakis Stadium helped Olympiacos, the Greek champions also showed far more skill and composure on the ball.
United will have to win by three clear goals in the second leg on March 19 to make it through to the quarter-finals, but Moyes has not given up hope just yet.
"The one good thing is that there is still a second game to come," the Scot said.
"We will do everything we can possibly do to reverse the 2-0 defeat."
Carrick was at a loss when asked to explain why United were so bad.
Asked what went wrong, Carrick said: "I'm not sure.
"We had good possesion in the first half. We had control of the game without penetrating their line, but at same time they weren't causuing us any problems.
"The goals came from nothing, but it obviously puts them in a great position.
"We didn't start the second half very well. A bit sloppy really."
Van Persie should have done better with a late chance he snatched at.
But Carrick did not want to aportion blame.
"You can't blame Robin; he's created his chance and nearly scored," he told ITV1.
"As players we have to stand up and take it on the chin.
"That's the business we're in. You take the good times and the bad times. We have to keep trying.
"You're looking for me to blame someone. As players we haven't been getting good results and as a club that's everyone involved. That's how we are judged."
Olympiacos manager Michel suspected that United could buckle under pressure given their lowly league position and that proved to be the case.
The Spaniard, who won the Spanish League six times with Real Madrid, hailed a historic win for the Greek club after the final whistle.
"The size of the opponent makes me believe this is the greatest win of my time here," Michel said.
"We have had many games against teams on the same level as United but this time we won. I am happy with the match and I am proud of my players."