A first Reds hat-trick for Philippe Coutinho stole the show but the quality of all the goals — particularly Sadio Mane’s volley for the fourth — proved once again when this team click into gear they are irrepressible.
“Nobody could imagine that it would go like this tonight,” Klopp said. “It was an all or nothing game for both teams.
“Spartak Moscow is a really good side, I know you won’t think so now but they are difficult to play against. We opened the game perfectly and after we took the lead we didn’t have to defend. It was a nice night at Anfield.
“It helps to get an early goal or two. I told them at half-time we needed to show that we learn from our mistakes and keep going. It’s really difficult when we go to the next gear and use the space, it was nice to watch tonight.
“I have nothing to moan about tonight, it’s all good. We changed the system a little bit, the boys did it really well. The defence was spot on, I really liked it.
“I don’t mind too much who we get — usually I always get Real Madrid, so we will see. We have no preferred opponents, it will be really nice after a long time. I love this kind of news.”
Needing only a draw to progress the Reds, who last time out blew a three-goal half-time lead to draw against Sevilla, left no room for doubt with the damage done by Coutinho (two) and Roberto Firmino inside 20 minutes.
Mane produced a superb volley and tumbling tap-in to sandwich Coutinho’s deflected shot for his treble — the first by a Liverpool player in the Champions League since Yossi Benayoun in 2007 — before top scorer Mohamed Salah scored his 18th of the season late on.
Finishing as Group E winners means avoiding the likes of Paris St Germain — the only team to outscore them in the pool stage — Barcelona, and Roma.
However, with Bayern Munich and Juventus potential last-16 opponents, the hard work has yet to begin but reaching the knockout phase for the first time since 2009 is a significant milestone after two previous failed attempts.
Liverpool’s fastest Champions League goal at Anfield after just three minutes and 51 seconds meant there were none of the nerves of Olympiacos, almost 13 years to the day, when Steven Gerrard set the Reds on their way to a fifth European Cup with his screamer in front of the Kop.
Coutinho’s cross was sailing well over Salah until Georgi Dzhikiya pulled the Egyptian down for the softest of penalties.
Liverpool’s captain for the night Coutinho scored his first penalty for the club which was not in a shoot-out and the systematic dismantling of Spartak began.
Mane, Salah, and Firmino combined with the Brazil international having the vision to delay his cut-back for Coutinho to run in for his 50th Liverpool goal.
Anfield screamed for another penalty when Mane’s cross hit the arm of Serdar Tasci but Firmino rammed home the loose ball before referee Szymon Marciniak had a chance to make a decision.
It was his sixth goal in the Champions League this season, the most by a Liverpool player in a single group stage, and the fourth time this season Liverpool had scored three goals in the opening 30 minutes of a European game.
Mane (twice) and Coutinho scored after the break but still the hosts were not sated and after substitute Daniel Sturridge missed from close range, Salah took the Reds’ tally for the campaign to 23, comfortably beating their previous best of 18 in 2007-08 and second only to the tournament record set this season by PSG (25).
Liverpool have now scored 32 goals in a nine-match unbeaten run since losing to Tottenham in late October and next host rivals Everton and their new manager Sam Allardyce on Sunday.
Karius, Gomez, Lovren (Alexander-Arnold 60), Klavan, Moreno (Milner 45), Coutinho, Can, Wijnaldum, Salah, Firmino (Sturridge 71), Mane.
Selikhov, Eshchenko, Tasci, Bocchetti, Dzhikija (Pasalic 59), Zobnin, Glushakov, Fernando, Promes (Samedov 75), Luiz Adriano, Ze Luis (Melgarejo 51).
Szymon Marciniak (Poland).