Manchester United manager Louis van Gaal said his team had been simply overwhelmed by Liverpool's high pressing during their one-sided 2-0 Europa League defeat at a raucous Anfield.
Daniel Sturridge, with a penalty, and Roberto Firmino scored as Liverpool claimed a deserved win on Thursday, and the hosts might have put the last 16 tie to bed had it not been for United goalkeeper David de Gea.
Ex-United players Paul Scholes and Rio Ferdinand, analysing the game for BT Sport, delivered stinging criticisms of their old team's display -- the former branding it "shambolic" -- and Van Gaal conceded his side had struggled with the Liverpool's intensity.
"I have seen we did not cope with the pressure, the high pressure of Liverpool," Van Gaal told his post-match press conference after the first ever European meeting between England's two most successful clubs.
"We had expected that and for me it was a surprise we did not cope with that because they did it the same way in the home match this year that we played against them (which United won 3-1).
"Because they provoked first, we could not play the ball from David de Gea to Daley Blind or Chris Smalling and they gave a lot of pressure and we could not cope with that.
"That raised the atmosphere. They created chances, but we had a very good goalkeeper and because of that we were (still) in the match."
Van Gaal described both Sturridge's 20th-minute penalty, awarded after Memphis Depay tugged back Nathaniel Clyne, and Firmino's late effort, which stemmed from a loose Michael Carrick clearance, as "cheap".
But he said that he had not seen a late incident in which United midfielder Marouane Fellaini appeared to catch Emre Can in the face with his elbow.
Liverpool manager Jurgen Klopp also refused to be drawn on the matter.
"There's nothing I should say," he said. "I'm not the referee. You can write what you want, but without something from my side."
The German was more effusive about his team's performance, asserting with justification that their victory had been "absolutely deserved".
- No limits for Klopp -
But while Liverpool will go into next week's return leg in a strong position to progress, he said that he did not want to lavish too much praise on his players.
"I can really celebrate and I can be really happy after this and say it's the best and the greatest, but I don't want to set a limit," he said.
"We can play better. Even in the first half. Because Manchester United didn't make too much pressure and we lost a little bit of patience and played too risky passes, which was really not necessary.
"We created problems by ourselves. Staying patient is a big challenge for all of us, not getting bored of simple passes.
"But a lot of things were really good, the pressing, counter-pressing. No time for anything for Man United, and that's how it should be."
Liverpool's fans set the tone for their team's performance with a rousing pre-match rendition of "You'll Never Walk Alone", the club's anthem, and Klopp paid tribute to them afterwards.
"The atmosphere tonight was unbelievable," he said. "Really great and I want to say thank you to everyone that was involved. That was Liverpool how I knew it before I came here."
While United now face a testing FA Cup quarter-final at home to in-form West Ham United on Sunday, Liverpool have a full week to prepare for the return leg.
Van Gaal urged his team's fans to take their cue from Liverpool's supporters by turning Old Trafford into a cauldron of noise.
"It's difficult because 2-0 is a very difficult result for us," said the Dutchman, who had emerged victorious from his first four meetings with Liverpool.
"But we have to create an atmosphere like Liverpool's fans have done."