The Red Devils faced an uphill task in front of their own fans after goals from Daniel Sturridge and Roberto Firmino consigned them to a 2-0 loss in the first leg at Anfield a week ago.
Old Trafford was a cauldron of noise as the match started at frenetic pace, and the home side began to dominate as the first half wore on, missing several good chances to take the lead.
They did get themselves right back in the tie just after the half hour mark when Nathaniel Clyne fouled Anthony Martial and striker converted from the spot to ramp up the atmosphere further.
However, United were dealt the killer blow after a flurry of chances before the break when Philippe Coutinho skipped past Guillermo Varela and dinked the ball inside David de Gea's near post to leave the hosts needing to score three.
The pace of the game continued after the break but by then, in truth, Louis van Gaal's side were already beaten as they came out on the losing side of the first ever European tie between the two teams.
The football on offer from the hosts was arguably better than most of the fare on offer at Old Trafford this season, but unsurprisingly that did little to assuage the anger of United fans on Twitter after the match, with the club getting it from all angles.
Plenty blamed Van Gaal:
Realistically, Manchester United a fantastic club has been brought to its knees through Louis Van Gaal and his horrible regime #MUFC— MUnitedHome™ (@MUnitedHome) March 17, 2016
What have we done to deserve LVG? The man has no winning mentality at all and he is destroying a great team #MUFC— Fusi Nkoala (@Iam_Fusi) March 17, 2016
LvG is an embarrassment. Watching his team lose & he just sits there writing notes whilst we get outplayed over 2 legs is shocking #MUFC— Everything Man Utd (@everything_utd) March 17, 2016
LVG your time is up, has been for months now. 3 pointless subs and Klopp ahead but brings on strikers. Embarassing AGAIN! #MUFC— STRIKEY (@Oi_Its_Strikey) March 17, 2016
LVG must go he is beating the life & the sprit out of our club. Awful tactics & strategy, terrible decision making at crucial times. #MUFC— CG22 (@Carly22GB) March 17, 2016
LVG's appointment has been a disaster from start to finish. He's failed us all. #MUFC— Lewis Allen (@lallen125) March 17, 2016
Some blamed the players:
This is a pathetic 2nd half performance. The players are showing a disgusting attitude towards the game. Embarrassing #MUFC— That_Martial_Lad (@Scott_MUFC0121) March 17, 2016
I don't mind losing. Of course we're going to lose games. It's the lack of desire and passion in the entire squad which angers me. #mufc— Connor Eccott (@CJEccott) March 17, 2016
For others, however, there are far deeper-rooted issues than just underwhelming displays on the pitch.
How the owners can sit there & watch what Fergie did for United, now being destroyed so quickly is disgraceful!#MUFC— Aizam Manaf (@AizamAfifi) March 17, 2016
Blame the owners and Ed Woodward for tonight and this season. Tactics and coaching contribute, but this club is rotten from the core. #MUFC— Marek Kubow (@kubomb) March 17, 2016
The board deserve every bit of this, they accepted failure when they decided not to sack Van Gaal. Our club is a total shambles. #mufc— Ä. (@Schweinmaster) March 17, 2016