The Reds began the game in the worst possible way as Nat Phillips blocked a Bruno Fernandes shot into the back of the net in the 10th minute. Jurgen Klopp then thought his side had won a penalty after Phillips was adjudged to have been fouled by Eric Bailly, before VAR overturned the call. Liverpool would eventually equalise on 34 minutes with Diogo Jota neatly flicking a Phillips pas past Dean Henderson.
Trent Alexander-Arnold, who had previously warned Manchester United's defence twice, then delivered a precise free-kick which saw Roberto Firmino head home just before the break to give the Reds a 2-1 lead. Firmino made it 3-1 early in the second half after a Henderson mistake, before Marcus Rahshord pulled United back within a goal.
Pressure from Manchester United set up a nail-biting finish but Liverpool finally locked up the three points when Mohamed Salah added the final touch to a well-executed counter-attack in the final minute. Liverpool picked a perfect time for their first league win at Old Trafford since 2014, as they pulled closer to the top four ahead of a trip to West Brom at the weekend.
There was a level of intensity and purpose to Liverpool's game that helped them forge some dangerous chances after going 1-0 down early. Trent Alexander-Arnold's performance in front of Gareth Southgate will have given the England manager something to think about as the defender's passing created the majority of Liverpool's big chances.
While the midfield battled well in their defensive duties, they didn't take care of the ball as well as they should, a number of questionable passes breaking down attacking phases. Liverpool's defensive display was desperate if not messy with Phillips in particular looking rash with his decision-making at the back.
Manager rating out of 10
7 -- The Liverpool manager's team selection offered balance and control in a game with the season on the line. Klopp also adapted well when 1-0 down with a noticeable shift in tempo from the Reds, who pressed higher and played with much more intensity.
Player ratings (1-10; 10 = best. Players introduced after 70 minutes get no rating)
GK Alisson, 6 -- The Brazilian goalkeeper almost gifted Manchester United an opener as Edinson Cavani intercepted a careless pass, and he couldn't do anything as a Bruno Fernandes shot was deflected in from close range.
DF Trent Alexander-Arnold, 9 -- The right-back has been at the forefront of Liverpool's chance creation this season and was unlucky to end the first half with just one assist from five key passes. Alexander-Arnold produced one of his best displays of the season with the ball and was alert when defending against United's late push.
DF Nat Phillips, 5 -- The 24-year-old's defensive display saw him at fault for two goals but a rollercoaster performance saw him prevent one off of the line and pick up an assist for Jota's leveller.
DF Rhys Williams, 6 -- There were questions over the young defender's inclusion in the lineup, but the 20-year-old's name was largely unheard on Thursday night, normally a good sign for a centre-back.
DF Andy Robertson 7 -- Liverpool's flanks were a favourable route to goal on Thursday night with the Scottish left-back linking well with Jota. The Scotland captain also worked hard to get back on defence and coped well with one of United's most dangerous threats in Rashford.
MF Fabinho, 7 -- His thoughtless pass in midfield was cut out in the build-up to Manchester United's opener in what otherwise was A strong display defensively. The Brazilian repeatedly closed down space quickly in the central areas, making it difficult for the ball to get into the feet of Fernandes.
MF Georginio Wijnaldum, 7 -- The Dutchman was slow to pick up the runner in the build-up to the opening goal, but it served as a wakeup call with the midfielder producing a solid display on both ends of the pitch afterwards.
MF Thiago, 7 -- Thiago is looking more comfortable with every game in Klopp's midfield and helped control possession under pressure. The 30-year-old's aggressive pressing forced a mistake which helped turn the ball over for Liverpool's third goal.
FW Diogo Jota, 7 -- The Portuguese winger worked hard throughout the game and reacted well to redirect Phillips' shot/cross into the back of the net. The 24-year-old should have put the game to bed in the second half but smashed a shot off the post.
FW Roberto Firmino, 8 -- The 29-year-old could have put Liverpool in the lead early on when opting to pass instead of shooting in a good area, but later came good with two important goals.
FW Mohamed Salah, 8 -- His frequent runs in behind the defence helped stretch the game and gave Liverpool a licence to play football in the opponent's attacking third. The Egyptian's tirelessness was rewarded in the final moments when he calmly finished to wrap up the three points.
MF Curtis Jones, N/R -- The Liverpool academy graduate displayed a calm head in the middle of the park and looked comfortable in both attack and defence.
FW Sadio Mane, N/R -- The Senegalese winger could have had a penalty when pulled down by Scott McTominay inside the box and provided pace on the counter. Shrugged off a Klopp fist bump afterwards as he clearly was unhappy that he didn't start.
MF Neco Williams N/R -- The young Welshman came on to help see the game out.