Sunday's Manchester derby is being billed as the match of the season so far, with a Manchester City victory ending the title race in early December, whereas a win for the Red Devils would reduce the gap at the top to five points.
Due to both teams getting off to excellent starts in the Premier League, pundits across the country have already sealed off this season as a two-horse race, with the champions certain to come from the North West.
Lurking just three points behind United are current champions Chelsea, waiting for any slip up in form by Mourinho's men. Here are four reasons why the title race isn't over yet, and why the west Londoners may yet celebrate another victory come May.
4. Antonio Conte
With the soundbite-heavy press conferences of Guardiola, Mourinho and Klopp, it is often forgotten that Chelsea possess a truly world-class manager in Antonio Conte, a tactical genius who led the west Londoners to the title at a canter in his first season in English football.
Before arriving at Chelsea last summer, he led a squad billed by Goal as 'the worst Italy team of all time' to within a penalty kick of the last four, going out to reigning world champions Germany after extra time.
After his summer heroics, it was fair to say there was a great deal of fanfare at Stamford Bridge for his arrival, with the Italian representing a clean break with the counter-attacking, defensive-minded past of Jose Mourinho. After the abject failures of the previous season, in which Guus Hiddink arrived midway through to lead Chelsea to an unremarkable 10th place finish, the Blues faithful were not expecting any kind of serious title challenge.
Despite all this, Conte, unburdened by the shackles of European football and tight schedules, led Chelsea on a club record 13-game winning streak from October to January, catapulting them to the top of the table where they remained until May, capturing the Premier League title with two games to spare, finishing seven points clear of second-placed Tottenham.
Not stopping there, Conte came within a whisker of emulating his compatriot Carlo Ancelotti and winning the double in his first season, going down 2-1 to an inspired Arsenal in the FA Cup final.
He has already weathered the usual storms encountered by Chelsea managers in years gone by, ignoring speculation about his job to lead his side to a current run of six wins in seven, after back-to-back defeats in September.
The Italian has already more than proven he is a match for his counterparts in Manchester, Liverpool and north London, possessing ample tactical nous to spearhead another challenge.
3. Heavy Rotation, Same Results
Going into Christmas and the New Year, Chelsea remain competitive on four fronts, with their final game of the Champions League group stage against Atletico Madrid coming up on Tuesday, and a Carabao Cup quarter-final at home to West Ham following later in the month.
With a slightly leaner squad than their title contenders, Chelsea have had to rely on youngsters such as Ethan Ampadu and Kyle Scott to fill in as substitutes, with a busy schedule and frequent midweek engagements.
Despite all this upheaval, the results have remained consistent, with the Blues top of their European group heading into the final round of fixtures, and bouncing back from their mini-slump in late September/early October to go seven Premier League games unbeaten, going to within three points of second-placed Manchester United.
This shows that despite a lack of depth when compared with other teams, a factor which Conte has bemoaned in the past, the tactical system the Italian has fostered is interchangeable to suit any combination of players, with fringe players such as Danny Drinkwater and Andreas Christensen coming into the team in recent weeks and proving more than capable to hold down a first-team berth.
2. 'Tis the Season to Be Jolly
In order to keep pace with runaway leaders Manchester City and their historic league-best start of 43 points from 15 matches, Chelsea will need a strong festive period to build a foundation for the rest of the season.
Thankfully, the fixture list is kind to the west Londoners, with no fixtures against any top-half team until they visit the Emirates early in the New Year. December features trips to basement dwellers West Ham and newly promoted Huddersfield, and home ties with Brighton, Stoke and Southampton, all winnable games for the reigning champions.
This provides a great opportunity for Chelsea to build momentum and keep breathing down the necks of the two Manchester clubs. After the Arsenal trip in early January, Conte's men do not face another top-six side until late February, with matchups against Leicester, Brighton, Bournemouth and West Brom unlikely to provide major opposition.
In comparison, the two teams above them have a few obstacles over the festive season, with league leaders Manchester City travelling to Old Trafford on Sunday, and hosting Tottenham next weekend. This is then followed by over-achievers Watford and Liverpool in early January, both currently in the top six. United possess a slightly easier set of fixtures beyond the showdown with their city rivals at the weekend.
1. Eden Hazard
With the spotlight being stolen everywhere by ex-Chelsea men Kevin de Bruyne and Mohamed Salah, the former being the shining light in an exceptional City side and the latter the league's top scorer, perhaps Eden Hazard has taken it upon himself to show the Premier League, and the world, why he is still its best player.
The Belgian has been back to his scintillating best this term, continuing his purple patch with two goals in Saturday's 3-1 victory over Newcastle, including an audacious Panenka penalty which left Stamford Bridge in awe of their number 10.
After the dire performances of Jose Mourinho's final days as manager, Hazard has shown in last season's run to the title and an excellent start to this season why he deserves to be talked about in the same breath as Neymar, Bale and Messi.
Chelsea's only true world-class player, he can flip a game on its head and is a bonafide match winner for Antonio Conte's men, delivering eight goals already in all competitions. De Bruyne and Salah may take all the plaudits, labelled by media everywhere as the ones that got away for the west Londoners, but the mercurial Hazard was the consensus best player in a title-winning team last season, perhaps with the exception of his tireless teammate and PFA Player of the Year N'Golo Kante.
He has continued in the same vein this time out, with his goals and all-around play looking primed to inspire Chelsea in a sustained title challenge for the rest of the season.