So Manchester United manager Ole Gunnar Solskjaer claims United are still the biggest club in town, eh?
Well, don't believe a word of it.
While the Red Devils have floundered since Sir Alex Ferguson's retirement in 2013, City have flourished - particularly under the tutelage of Pep Guardiola.
Under the Spaniard, the Sky Blues have built a dynasty, smashing records and winning titles as they turned the tables on their fiercest rivals.
As things stand, the Citizens are top dogs in Manchester, though Solskjaer has denied this is the case. To back his claim, the Norwegian - like many of those at Old Trafford - took a trip down memory lane, using United's past successes as evidence that they remain the biggest of the two giants, as per BBC.
Here, 90min takes a look at why Solskjaer is sorely mistaken.....and why City are the real giants of football in Manchester.
Only one team in the history of English football has ended a first division season with 100 points. That team was Manchester City in 2017/18.
Of course, that was not the only record broken by Guardiola's recruits as they stormed away from United to collect their third Premier League title. Sergio Aguero and co. also posted the highest number of wins and goals in a single season, the biggest goal difference and the greatest winning-margin at the top of the table.
This was revolutionary football that ripped up the rulebook. This was the most devastating, electrifying side England has ever seen.
Worst Start Since the 1980s
How can the biggest club in Manchester be 11 points behind their rivals after 15 rounds of action?
United are currently closer to 19th-place Norwich City than they are to the Sky Blues following their worst start to a top-flight campaign in 31 years.
Right now, the gap between the two Mancunian clubs is cavernous.
The Domestic Treble
It took 139 seasons for an English team to finally win the domestic treble, though it was well worth the wait for Citizens supporters.
Last year, the Sky Blues were far and away the dominant force in the country, gobbling up everything that was on offer, whilst United were left to celebrate... missing out on the Champions League. Yay.
Yes, Solskjaer and his men had to watch on as their neighbours did what Fergie never could and collected all three of the Premier League, FA Cup, and EFL Cup in the same campaign.
The Scotsman may have won a more impressive treble in 1999, but that was 20 years ago. There'll be plenty of United fans who weren't even alive to see it.
The European Front
In May, City qualified for their ninth straight Champions League campaign, with Guardiola's side firmly on course for a tenth. That's consistency. That's how you seal your place amongst Europe's elite.
Comparatively, United are playing their third season outside of the competition since Ferguson departed, and have only reached the quarter finals twice in that time.
The Sky Blues, on the other hand, have made the last eight in three of the last four campaigns. It should be obvious which team inspires more fear on the continent.
Doing the Double
Head-to-head meetings should give an indication of who rules Manchester.
2009/10 represents the last time United did the double over City, whereas 2018/19 was the most recent season in which the Sky Blues recorded two victories in the derby.
City did the same thing in 2013/14 and 2011/12, with the Etihad Stadium outfit beating their rivals on seven occasions in the post-Fergie era.
United, meanwhile, have just three derby triumphs in the Premier League since Sir Alex hung up his chewing gum. It's clear what tipped the scales in the Sky Blues' favour.
The Alexis Sanchez Fiasco
Why did United go all out to sign Alexis Sanchez in January 2018? Because they were desperate to prove they were the biggest club in Manchester.
Pep had been sniffing around the Arsenal star when the Red Devils decided to make him an offer he couldn't refuse, United agreeing to pay the forward up to £500,000-a-week.
That ludicrous sum of money - which City rightfully baulked at - earned them five goals in 45 appearances. However, the main thing Sanchez brought to Old Trafford was more doom and gloom.
The Chilean became a symbol of everything wrong at United. Senseless spending, a defeatist mindset and a lack of effort saw the Sky Blues steam away from the Red Devils.
You can say all you want about Solskjaer giving the youth a chance, it doesn't excuse a 2-1 loss to Kazakhstani champions Astana in November, nor a fortuitous 1-0 victory over the same side at Old Trafford.
People don't expect big clubs to struggle against sides like Astana or third-tier Rochdale, yet it wasn't particularly shocking to see United in trouble against them.
Now, we anticipate these lacklustre performances from Solskjaer's boys, because we don't view them as the powerhouse they once were. We expect mediocrity, and that's often what we get.
Mourinho's Greatest Achievement
United's demise can be summed up by Jose Mourinho's comments about his time at the Theatre of Dreams, as reported by ESPN.
The Portuguese claimed that winning the Champions League with underdogs Porto was not his greatest achievement in football
According to the man himself, Mourinho's finest accomplishment was getting United to finish as runners-up in the top-flight in 2017/18, when they were 19 points behind City.
That's how big the gulf between the two clubs is. There's no comparison to be made, t