Personal animosity is the main source of intrigue as Jose Mourinho's Manchester United host Antonio Conte's Chelsea this weekend.
Manchester City's gallop to the title looks unlikely to falter but, in previous years, this fixture was the game that decided who would be the likely kings of England.
Old Trafford has played host to some unforgettable encounters between Untied and Chelsea and it feels like the right time to take a trip down memory lane.
April 2010 - Manchester United 1 Chelsea 2
After claiming three consecutive Premier League crowns, United were in pole position for another as they welcomed second-placed Chelsea to Old Trafford at the start of April.
But Alex Ferguson was left fuming as Didier Drogba's blatantly offside winner saw the Blues take top spot on their way to the title.
Joe Cole's cute backheel secured a first-half Chelsea lead and Drogba then arrived from the bench to thrash a finish beyond Edwin van der Sar - the flag staying down despite the forward's mistimed run - with Federico Macheda's instant response not enough to set United back on track.
May 2009 - Manchester United 2 Chelsea 1
Having spent over two decades determinedly chasing down Liverpool's 18 league titles, Ferguson moved United to the brink of parity with their long-time rival as he masterminded victory over Chelsea.
Javier Hernandez - one of the signings of the season - rolled a finish past Petr Cech inside the opening minute and captain Nemanja Vidic nodded a second midway through the first half as the title celebrations got under way a week before top spot was confirmed.
Frank Lampard got a goal back after the break, but the Blues left Manchester six points off the pace with just two games remaining.
September 2007 - Manchester United 2 Chelsea 0
Chelsea legend - and current United boss - Mourinho left Stamford Bridge days before a trip to face the champions, with Avram Grant, whose presence on the board had unsettled the manager, taking charge.
His first taste of Premier League football did not go to plan as John Obi Mikel contentiously saw red with just over half-an-hour played.
The Blues held out until the final minute of the first half before conceding to Carlos Tevez, with Louis Saha's penalty at the same stage of the second period finishing Grant's men off.
December 2001 - Manchester United 0 Chelsea 3
After three consecutive titles, United had endured an awful start to the season - and it got worse as Chelsea stunned the champions at Old Trafford.
With Ferguson deploying captain Roy Keane in the centre of defence, Mario Melchiot nodded an early opener and further goals came after half-time from Jimmy Floyd Hasselbaink and Eidur Gudjohnsen.
"I don't think we will win the title now," was Ferguson's assessment. He was right.
September 2000 - Manchester United 3 Chelsea 3
As with Grant, Claudio Ranieri's first game in English football took him to Manchester as Chelsea sought to end a five-game winless run in the league at the home of the champions.
The Blues started brightly and took the lead through a stunning Hasselbaink strike, but a crazy first half saw Paul Scholes respond with a beauty of his own and a quickfire double from Teddy Sheringham and David Beckham handed United a two-goal lead.
However, Graeme Le Saux would prove the star of the show, making a stunning goal-line clearance from Andy Cole between a pair of left-wing dashes that created goals for Tore Andre Flo and ensured Ranieri left with a point.
