Watch Man United v Liverpool, live on Sky Sports 1 & HD1 on Saturday
Sir Alex Ferguson's side have been nothing less than imperious in winning their last 11 league games to usurp Liverpool at the Premier League summit; a run of results which has seen them move seven points clear of their Merseyside rivals with a game in hand.
Liverpool arrive in Manchester in fine fettle themselves, as while in the league they have faced accusations of being ponderous, against Real Madrid on Tuesday they were positively dynamic and some of their football was as aesthetically pleasing as has been seen this season.
At the hub of their best work were somewhat inevitably Fernando Torres and Steven Gerrard, whose telepathic relationship must be in full working order if Rio Ferdinand and Nemanja Vidic are to be unduly ruffled.
United negotiated a tie against Italian champions Inter Milan easily enough on Wednesday to book their own passage into the last eight, but were not at their fluent best in a performance that will give Benitez food for thought.
It is, though, far from a two-horse race for the title as a rejuvenate Chelsea under Guus Hiddink welcome Manchester City to Stamford Bridge.
Tuesday's trip to Turin summoned the ghosts of Mourinho-past as the Blues were gritty and resolute in eking out a 2-2 draw, which saw Didier Drogba again back to his bullish best after an otherwise forgettable season under Luiz Felipe Scolari's less accommodating stewardship.
City remain the division's most Jekyll and Hyde side and will look to put their poor away form to one side in order to provide a stern test of Hiddink's men. Sunday's game is live on Sky Sports 1 & HD1.
Making it four from four English clubs to make it into the last eight of the Champions League are Arsenal, whose performance in Rome showed character if not the style the continent's highest stage usually brings out in Arsene Wenger's side.
At the Emirates on Saturday it will be a case of back to reality as a robust Blackburn - fresh from a massive three points at Fulham in midweek - will provide the type of no-nonsense archetypal British fare that Arsenal normally find less appetising than Europe's haute cuisine.
Anything less than a maximum haul for the Gunners will leave the door open for Aston Villa to open up a sizeable gap in fourth, as they host Tottenham a day later in another game that can be seen live on Sky Sports.
Spurs' solid form of late has propelled them to the relative safety of 12th but in the most remarkable of seasons, such a lofty standing sees them only four points off the drop zone.
Everton are a side with aspirations of establishing themselves in the top four and in the second half of the campaign have found a consistency in their performance that has suggested it may not be beyond them, should David Moyes be handed the chequebook in the summer. On Saturday they face a Stoke City side that is making a real fist of retaining its top-flight status, at fortress Goodison Park. The return of in-form James Beattie to Merseyside provides a further intriguing sub-plot.
If ever a contest deserved being billed as the proverbial 'six-pointer' it is Portsmouth's trip to the Riverside to face relegation rivals Middlesbrough.
The experience of Paul Hart and Brian Kidd has steadied a ship going the same way as the Titanic under Tony Adams, but nonetheless they still find themselves in the bottom three courtesy of Blackburn's surprise win at Fulham.
Middlesbrough, meanwhile, are drowning faster than Leonardo Di Caprio. Kate Winslet and a piece of driftwood couldn't save him and, on recent form, it will take more than Gareth Southgate to keep up a Boro side that have won just once in their last 17 league games.
Hull City's remarkable start to their debut Premier League campaign has long since been forgotten, as a freefall has seen Phil Brown's side looking nervously over its shoulder. A win in their last league outing against Fulham, who seem to be the team to face when you badly need a boost, has rejuvenated spirits at the Tigers and a home game against Newcastle United could provide further fillip.
Michael Owen's scheduled return should at least provide Newcastle with a cutting edge as they look a side in serious trouble, given a tough final fixture furlong that awaits them and a lack of any real form.
North East rivals Sunderland have been going about their business in a quietly efficient manner since Roy Keane decided the Stadium of Light was no longer for him, as they host a Wigan side, replete with Geordie boss Steve Bruce, that is looking above rather than below for the first time since they won promotion in 2005.
Fulham's squandering of a lead to lose to Blackburn will worry boss Roy Hodgson and given his side are no Judith Chalmers when it comes to travel, a trip to Bolton is perhaps not what the doctor ordered.