It was just under two weeks ago that Liverpool ruined Man City's hopes of getting closer to the top of the Premier League table.
Fabinho, Mohamed Salah and Sadio Mane put City to the sword as Pep Guardiola's men were denied the chance to cut Liverpool's lead at the summit.
It was arguably the most important victory Jurgen Klopp has masterminded against City since arriving at Anfield, but it wasn't the first time he's hurt their title chances.
Indeed, it took Klopp just over six weeks to lay down a marker to Liverpool's title rivals in what was akin to the Reds' coming out party under the German.
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The date was November 21, 2015 and the location was Man City's Etihad Stadium.
City, then in the final throes of Manuel Pellegrini's reign at the Emirates, had endured an inconsistent start to the season. They didn't concede a goal in their first five games, winning all of them, and had also put six and five past Newcastle and Bournemouth respectively.
But cracks had started to show in defeats to West Ham and Tottenham.
Even so, Klopp was still very much in the early stages of his reign and had overseen just two Premier League victories and although one of those had come at Chelsea, the London club were marooned in the bottom half of the table.
So the trip to City represented Klopp's most difficult test yet and Liverpool, who hadn't won a league match at the Etihad since 2009, were massive underdogs.
But two weeks after losing 2-1 at home to Crystal Palace, Klopp's reign truly came alive when the Reds demonstrated what they could do when the former Dortmund manager's tactics were implemented exactly as they should be.
It was a glimpse of what the future held for Liverpool under Klopp and also a taster of what an important part Roberto Firmino would soon play.
The Brazilian had been shunted around the front of Liverpool's attack under Brendan Rodgers, but Klopp switched him to a central role and his Anfield career took flight.
And at the Etihad Liverpool danced to a Samba beat as Firmino dovetailed perfectly with Philippe Coutinho to put City to the sword.
The Reds were relentless, pressing City from the front and stopping Pellegrini's side from getting out their own half.
Soon the home crowd had started to turn and the hapless Eliaquim Mangala and Martin Demichelis were making mistakes.
Liverpool took full advantage and within seven minutes Mangala, a £32m signing from Porto, had put through his own net.
Coutinho scored next before Firmino got his first goal for the club just after the half hour mark.
Sergio Aguero would pull one back - as he often does at the Etihad against Liverpool - but the Reds put an exclamation mark on the victory with a thumping Martin Skrtel volley.
City had felt the full force of the German's tactics and the Reds boss would hail a "perfect" result after the final whistle.
It was an early marker for Klopp, who by and large has had City's number since he arrived at Anfield.
The Liverpool boss has faced them 13 times in all competitions, winning seven times, drawing three and losing three times.
The first meeting contributed to denying City a Premier League title as Leicester caused an upset for the ages.
Klopp will hope the most recent victory also denies City another title - but this time his Liverpool team will be the beneficiaries.