Manchester City exacted revenge for their Premier League defeat to Chelsea earlier this month by knocking Jose Mourinho's Blues out of the FA Cup at the fifth round stage with a 2-0 victory on Saturday night.
As the better team for pretty much all of the match, City built on their early dominance when Stevan Jovetic enjoyed his best moment in English football with a stylish finish beyond Petr Cech just 16 minutes into the clash at the Etihad Stadium.
He and his club could have had more during what was a dominant first half, and despite Mourinho's best efforts he couldn't change the flow of traffic in the second period, either.
City substitute Samir Nasri settled the game as, just six minutes into his first appearance in a month following injury, he turned home David Silva's cut back to double the lead and end Chelsea's hopes.
The win serves as a huge boost to Manuel Pellegrini's side ahead of their clash with Barcelona in the Champions League on Tuesday, and keeps alive their hopes of an unprecedented quadruple this season.
Here are six lessons we learned from the Etihad Stadium.
It's still possible, and barring a disastrous result at home to Barcelona on Tuesday night the dream is going to extend into March.
Logic dictates that Manchester City won't win four trophies this season, but the longer they keep that hope alive, the more prestige and gravitas is added to what at times has been a special season already.
The nerves and anxiety that accompanied City's last two games were absent here, as City took hold of the match from the very beginning and refused to be bullied by Chelsea for the second time inside two weeks.
They'll await the quarter-final draw with interest, but with the Barca game, the Capital One Cup final and the Premier League title race all on his agenda, City boss Manuel Pellegrini is a busy man right now, but no manager would want to swap places with him.
A few substitute appearances, which admittedly included the fourth goal of five at Tottenham, and a disappointing start in the fixture away at Norwich were one thing, but here was Stevan Jovetic finally showing Manchester City fans what he's all about.
You cannot overestimate just what the confidence gained by scoring a big goal in a big game will do for the Montenegrin, who finished expertly beyond Petr Cech 16 minutes into a contest that was so crucial for the home side.
Given the defeat they experienced to the same opponents on this same ground 12 days ago, it was crucial that City scored when they were on top during this game, as they undoubtedly were during the vast majority of the first half.
Jovetic might still find himself back on the bench when Barcelona come calling on Tuesday, and indeed when Sergio Aguero returns from injury, but in the closing and crucial weeks of the season his freshness might well be vital.
John Terry's absences during the managerial reigns of both Roberto Di Matteo and Rafael Benitez were quite often expected, and they didn't seem to harm the Blues either given the fact that they won two European trophies under the aforementioned managers.
The return of Jose Mourinho has seen the Portuguese choose to rely on his old favourite, though, with Terry ever present in his Premier League defence all the way up until the 3-0 win over Newcastle last week.
Terry wasn't missed there, but his defensive organisation certainly was, both in the 1-1 draw at West Bromwich Albion in midweek and here, as Chelsea were unable to repeat the Terry-inspired organisation that led them to the 1-0 win at the Etihad which has so shaken up the title race.
Alongside the thankfully fit Gary Cahill, Terry is going through something of a renaissance, and they will welcome him back with open arms if he is—as expected—fit to return for the league clash at home to Everton next Saturday.
It was the injury to metronomic Brazilian midfielder Fernandinho that so disrupted City before the league clash with Chelsea 12 days ago, with Pellegrini opting to play Martin Demichelis in the centre of midfield to disappointing effect.
Here, though, Pellegrini pitched both Javi Garcia and James Milner into the centre of the action, with both players providing the shield for Yaya Toure to use as he went forward.
The decision lessened City's often fearsome attacking threat (with Jesus Navas the player dropped for Garcia), but it certainly solidified them and provided Pellegrini with a useful blueprint to how he should approach the big games in the future, of which there are plenty.
Earlier this month the Chelsea trio of Nemanja Matic, David Luiz and Ramires dominated midfield as Demichelis floundered, but here Garcia and Milner were strong, with the latter making a clever run in the build-up to Jovetic's goal.
Fernandinho is that important to this City side; they might need two players to replace him.
The Manchester City team picked by Pellegrini for this clash was always going to be a huge topic of discussion here, with Barcelona due at the Etihad in the Champions League in just three days time.
In the event, the Chilean opted to start with the returning Samir Nasri on the bench with Spanish forward Alvaro Negredo, who suddenly looks to be a huge figure against the Catalans, sat there alongside him.
Both watched on as interested spectators for the majority of the match, with Nasri replacing Stevan Jovetic with half an hour to go to almost immediately double City's lead and Negredo coming on for Edin Dzeko late on, but expect the pair to be far more heavily involved when Lionel Messi and company come calling in midweek.
Nasri's movement and incisiveness from behind the forward(s) will be crucial, whilst Negredo knows all about the Barca defence having played against them countless times in La Liga, and he'll fancy his chances against a defensive outfit which haven't always convinced in his homeland this season.
He might have enjoyed sticking the boot into anyone and everyone over the past few weeks, but perhaps Jose Mourinho's mind games have gone into overdrive simply because he knows that his Chelsea team are sorely lacking up front?
Samuel Eto'o is 32 and cannot be regarded as anything other than a stopgap signing, Fernando Torres is fragile in more ways than one and Demba Ba barely registers in his manager's consciousness. And so the acquisition of a top-class forward must be uppermost in the Portuguese's mind in the summer.
Of course, a club becomes a much more attractive proposition when they are the Premier League champions, and the Blues can still become that this season, but to truly kick on and realise their manager's dreams they surely need a better front man.
They can't keep relying on Eden Hazard, Willian and Oscar for their attacking impetus, because it was lacking here.