The dust settled, the hangovers were finally a distant memory, but the smiles remained.
For Manchester City fans the score line was magnificent, a chance for the fans of the blue side of the city to stick it to their red neighbours and preach their triumph. Nothing could be better than that score line, they thought. Or could it?
When it was time for reflection this week it turned out there was. The performance. When they won 6-1 against Manchester United two years ago they had played well, but it was against 10 men with three goals scored very late. This time they didn't play well, they played great.
Deep down this is what City fans will keep to themselves, for now: The dawn of a new era where their marquee players stepped up for the new man in charge.
City's 4-1 thumping over rivals Manchester United on Sunday was of significant importance for the fans, but it was even bigger for the club's new manager.
When he was hired, Manuel Pellegrini was simply not a household name in England, despite having a very impressive coaching resume in Europe. Yet, here he was put in charge of one of the biggest clubs in the land where anything other than a Premier League trophy would be a disappointment.
Following the game the Chilean was his usual charming self to the press, talking about the performance, but then he slipped in this little nugget mid-sentence: "We must continue improving, trying to play another way, change a lot of things, every day we are improving."
It was a phrase lost on the interviewer, who wanted to talk how great City were but it will not have been lost on the men in charge of the club.
Contrast Pellegrini's comments to what Jose Mourinho is currently doing at Chelsea.
Suddenly, the world knows about Mourinho's desperate desire to change the team's style, because Mourinho continues to tell the press about it. Mourinho talks about how he didn't like how Chelsea played before and how the club's Player of the Year last season, Juan Mata, must watch and learn to adapt to his style.
Whether Mourinho is right or not is not the point at the moment. The point is the general consensus throughout the world is that this is Jose's team and when/if Chelsea succeed it will be because of him... A manager who won't play one minute in the Premier League this season.
Meanwhile, at Manchester City, Pellegrini is quietly going about his business making changes that will bring the best out of his players and allow what happens on the pitch, not in the media room, to dictate the club's identity. This is one of the main reasons why Pellegrini was hired, Roberto Mancini was fired and why Mourinho was never considered for the City job by Chief Executive Officer Ferran Soriano and Director of Football Txiki Begiristain.
Soriano's intellect and business acumen combined with Begiristain's football intelligence makes them a dynamic duo not to be ignored inside the landscape of English football. To understand their beliefs and attitudes it is important to know the roles they played at Barcelona and, in this case, specifically in the recruitment of a new manager.
At the end of the 2006-07 season Barcelona - a year after winning the Champions League and La Liga - lost their domestic league on goal-difference to Real Madrid. Their manager Frank Rijkaard could not lose his job just 12 months after conquering Europe, but deep down Barca's Director of Football, Begiristain, knew he wasn't the man to take them forward.
In Graham Hunter's excellent book Barca: The Making of the Greatest Team in the World, it is revealed that he began to search for the Dutchman's replacement as early as October 2007, despite the change not taking place until the summer of 2008.
In a discussion about considering Jose Mourinho for the Barcelona job, Soriano tells Hunter: “The first board discussion about Mourinho was in December 2007. Retaining Rijkaard had proved a mistake.”
A mistake the pair have clearly learned from and one that helped prompt the sacking of Mancini and the hiring of Pellegrini. It was also a decision most fans were against and most media thought was premature. The rest of the chapter offers a fascinating look at Mourinho's attempts to persuade Barcelona to hire him including Begiristain's reasons for not hiring him. After reading this it is clear why the former Spanish international had grown frustrated with Mancini at City.
Begiristain couldn't imagine Mourinho understanding the club didn't want or need outbursts in the media two or three times a week. What's more, the Basque felt that the Barca he was trying to build valued respect for the opponent, honour in defeat, dignity and other fragile concepts more highly than Mourinho did at that time, or perhaps ever would.
Now Mancini is certainly no Mourinho when it comes to loving the sound of his own voice and Barcelona's players are certainly no choir boys to opponents or referees when things go against them, but the point is how highly Begiristain values these traits. This is a brilliant football mind who thinks about a club from top to bottom, who thinks a club's branding should start with its name and badge, followed by its players, not what was happening at City last season and currently with Mourinho at Chelsea.
More from Hunter on Begiristain:
He was 100% sure, and remains to this day, that Barca would have trained well, played decent, if pragmatic, football and won trophies under Mourinho. However, he was equally sure that these would become pyrrhic victories compared with what Mourinho would cost the socios, the board, Barcelona's international brand and a host of other intangible concepts that the club saw intrinsic.
Begiristain feared that Mourinho felt he was more than the club.
Manchester City on the field simply didn't meet their standards last season (with no wins in the Champions League, an FA Cup final loss to Wigan and not coming close to contending for the title) but it was off the field that revealed even more concerns, with constant negative stories in the press surrounding the likes of Mancini, Mario Balotelli and Carlos Tevez. City needed a new identity with a strong spine coming via a professional manager who wouldn't become bigger than the club itself. They didn't need Mourinho and his current antics at Chelsea will bring smiles inside the Manchester City boardroom. Just like that, there is a new distraction in town.
City can go quietly about their business on the field and thanks to Pellegrini, Begiristain and Soriano, it's now the players, evolving under a new regime, who will make the headlines… and that's the way it should be.
Join Alastair Connolly and myself live on TSN and TSN2 at 9:30am et as we get you set for Aston Villa vs. Manchester City and Manchester United vs. West Bromwich Albion.