Group E winners with a 7-0 demolition of Spartak Moscow at Anfield on Wednesday.
Selected to help secure the three points that would sew up top spot, Coutinho’s hat-trick headlined a fearsome display of attacking speed and precision as the home side ran riot from the outset.
The Brazilian – wearing the armband as Jordan Henderson watched on from the bench – was on target twice in the opening 15 minutes to dispel any doubts over their command of a seeded berth in the last 16.
He first converted from the spot in the fourth minute and then capped off a classy attacking move for a second, before Roberto Firmino got in on the act by making it 3-0 in just the 18th minute.
Liverpool had coughed up a three-goal lead against Sevilla in their previous European outing but there was never any hint of that transpiring again as Sadio Mane bagged a brace either side of Coutinho’s third and Mohamed Salah sensationally added a seventh late on to cap a four-goal second half.
Jurgen Klopp will rue the first-half loss of Alberto Moreno to injury as the only blot on an otherwise sensational performance, which improved their group-stage haul to 23 goals – three clear of Manchester United’s previous record for English clubs.
#UCL last 16 awaits… pic.twitter.com/RbBkH7FFAl
— Liverpool FC (@LFC) December 6, 2017
Liverpool’s early onslaught began from the spot, Coutinho coolly sending the goalkeeper the wrong way after Salah had been blatantly dragged down by Giorgi Jikia.
The ease with which that penalty was won failed to convey the hosts’ attacking power and they immediately set about putting on a show.
Mane, Salah and Firmino combined for a superb one-touch move in the 15th minute, the latter squaring for Brazil team-mate Coutinho to finish back across a helpless Alexander Selikhov.
And the game was, incredibly, all but over just three minutes later. Firmino this time turned scorer as Mane’s delivery from the right deflected off Serdar Tasci’s arm and dropped kindly for him to poke home.
Loris Karius – continuing his run in Europe – was not without occasional work, first denying Luiz Adriano and later saving comfortably from Quincy Promes.
Just as all appeared perfect for the Reds, their excellent opening half ended on a slightly sour note with a visibly upset Moreno limping off after blocking a shot, requiring Klopp to call on James Milner.
They lost nothing with the change. Milner delivered an inviting cross for Mane to thump home on the volley less than two minutes into the second half.
Spartak’s defence had been scrambled from the outset and they were punished for a fifth time in the 50th minute, Coutinho finding space in the area to wrong-foot Selikhov with a deflected effort off Salvatore Bocchetti.
3 – Philippe Coutinho has scored his first ever hat-trick for Liverpool in all competitions. Sublime.
— OptaJoe (@OptaJoe) December 6, 2017
Klopp moved to safeguard against further injuries by removing Dejan Lovren on the hour and and Firmino soon followed, replaced by Daniel Sturridge.
It was Sturridge who provided an unselfish low pass across the face of goal for Mane to rather awkwardly turn in his second and Liverpool’s sixth in the 76th minute, bfeore Salah fired in from Milner’s header to put the final seal on the Reds’ emphatic return to the knockout stages for the first time since 2008-09.