And so it is, Liverpool will not go the 2019/20 Premier League season unbeaten after falling spectacularly off the horse at lowly Watford on Saturday evening.
The Hornets delivered the killer sting through a brace from Ismaïla Sarr and a Troy Deeney finish, putting paid to the Reds' hopes of matching Arsenal's 'Invincibles' and simultaneously ending the Merseysiders' 18-game winning streak on the day they could have set a new record by going one further.
Momentous stuff, run routed. Cue wild celebrations on the red side of north London.
And while the context is fascinating, the scoreline itself is quite something; relegation-threatened Watford thrash runaway champions-elect Liverpool 3-0, not just a tight 1-0 or close 2-1 - an absolute thumping.
But where does it rank among Jürgen Klopp's biggest defeats as Liverpool boss? 90min have had a look see...
Disclaimer: His side have lost 2-0 a few times, but 3-1 = more goals conceded, so, yeah.
6. Swansea 3-1 Liverpool (1/05/2016)
With a Europa League semi-final second leg on the horizon against Villarreal, Klopp opted to field the youngsters on the road at Swansea, with Pedro Chirivella, Kevin Stewart and Sheyi Ojo all starting.
It was a decision that backfired in this match at least as an André Ayew brace and Jack Cork strike dented Liverpool's European hopes.
Christian Benteke did manage to pull one back (yes, really) and Liverpool overturned their one-goal deficit in the second leg against the Yellow Submarine, winning 3-0 at Anfield to progress to the final, where they would ultimately lose out to Sevilla.
5. Leicester 3-1 Liverpool (27/02/2017)
Almost two years to the day of this latest defeat to Watford, Liverpool were comfortably beaten by reigning champions Leicester at the King Power.
A Jamie Vardy double and Danny Drinkwater strike (yes, really) had the hosts 3-0 up before Philippe Coutinho pulled one back.
4. Watford 3-0 Liverpool (20/12/2015)
Yes, Jürgen Klopp has been on the end of a trouncing at Vicarage Road before,
Now Man Utd man Odion Ighalo scored two. That's got to sting.
3. Watford 3-0 Liverpool (29/02/2020)
Déjà vu, as they say in France.
Per Opta, on Saturday
2. Tottenham 4-1 Liverpool (22/10/2017)
Not a great day on the road for the Reds, as Harry Kane and co had a field day against a hapless Liverpool defence at Wembley, Spurs' temporary home at the time.
Spurs were third and Liverpool were way down in ninth after a poor start to the season - strange to think about now.
Seven of that starting lineup are still at the club today, although the result notably pre-dates the signing of Virgil van Dijk.
1. Manchester City 5-0 Liverpool (9/09/2017)
A first-half red card for Sadio Mané saw Klopp's side capitulate at the hands of Pep Guardiola's Man City side, who would eventually go on to win the league.
The Reds were already a goal down when Mané karate kicked Ederson in the face, and the Cityzens were ruthless in their dismantli of the ten men before them.
Again, this was pre-Van Dijk Liverpool, but a hefty, hefty defeat nonetheless.