Liverpool face a huge task to reach the Champions League last four after a humbling 2-0 defeat to holders Paris Saint-Germain in their quarter-final first leg at the Parc des Princes.
Desire Doue scored a deflected opener and Khvicha Kvaratskhelia punished poor defending to add a brilliantly-taken second in a one-sided contest in Paris as Liverpool were condemned to a fourth consecutive away defeat for the first time since April 2012.
The margin of defeat would have been greater if not for some wasteful Paris Saint-Germain finishing and good goalkeeping from Giorgi Mamardashvili, who made fine saves from Doue, Kvaratskhelia, Ousmane Dembele and Achraf Hakimi as the hosts dominated.
Luis Enrique's side were also aggrieved not to be awarded at least one penalty, with VAR overturning the referee's decision to penalise Ibrahima Konate for a foul on Warren Zaire-Emery, then opting not to penalise the defender for a push on Nuno Mendes.
Liverpool were fortunate only to lose by two goals having been comprehensively outclassed on the night and will need to show major improvement in next week's second leg at Anfield, having only mustered three shots, and none on target, on a poor night in Paris.
Arne Slot changed his system to a back five in an attempt to contain Paris Saint-Germain's considerable threat and found no place for Mohamed Salah, who was an unused substitute, only two weeks after confirming his exit at the end of the campaign.
The tactical adjustment did not faze the hosts, though, who deservedly added to Doue's deflected opener when Ryan Gravenberch failed to track Kvaratskhelia, who latched onto Joao Gomes' pass before cutting inside classily to slot home.
Slot threw on the fit-again Alexander Isak for his first appearance since December as he tried to inspire a response but Liverpool never looked like getting back into the game and continued to be cut open by Paris Saint-Germain in the closing stages.
Having already exited the domestic cup competitions, and with their hopes of retaining the Premier League title long over, the defeat puts their final route to silverware in severe jeopardy.