There, United’s two greatest rivals contested the finest match of the season and everything about the love-in between Guardiola and Jurgen Klopp seemed to contrast so starkly with the way Jose Mourinho and his team operate.
Yet there was plenty to admire in this routine victory over a Stoke side whose brand-new manager, Paul Lambert, had not fancied taking charge just yet.
Not least two sumptuous first-half finishes from Antonio Valencia and Anthony Martial — Ant music to turn up the jukebox and upset the noisy neighbours just a touch.
Romelu Lukaku added the third with class and composure — and the Belgian centre-forward ought to enjoy playing alongside Sanchez.
The versatile Chilean’s imminent arrival adds another A-list attacking talent to a theatre which has too often felt like a setting for kitchen-sink drama over the 4½ years since Sir Alex Ferguson bowed out.
With Paul Pogba, Zlatan Ibrahimovic, Lukaku and Sanchez at the same club it would begin to feel like Real Madrid’s Galactico era, only without so much fun.
Of course, as that Real team showed, buying up Hollywood names is no guarantee of any sort of success.
But after Mourinho had moaned long and hard about City’s superior spending power, his board have proved that United are not exactly trawling the food banks.
Perhaps he can stop pining for Paris Saint-Germain and enjoy this place a little more.
Sanchez scores them, makes them and would add X Factor to a United team which often lacks imagination however much has been spent on its construction.
His arrival ought to cheer Mourinho, whose moods have been swinging between misery-guts darkness and venomous spite in recent weeks.
Anthony Martial scores sublime curled goal from quality Paul Pogba assist against Stoke
On this ‘Blue Monday’, statistically the most depressing day of the year, Stoke fans would hardly have been cheered by the appointment of Lambert.
The former Aston Villa and Wolves boss can often make Mourinho sound like Eric Morecambe singing ‘Bring Me Sunshine’ and he does not have an impressive recent track-record either.
Stoke’s board had previously warned their fans that while they had been looking to replace Mark Hughes, options were thin on the ground.
Having sacked the Welshman after the FA Cup humiliation by Coventry, they now seem to have proved their own point.
With Stephen Ireland playing off Peter Crouch, and Darren Fletcher behind them in midfield, this Stoke line-up reminded you of one of those Sky Sports ‘Premier League years’ compilations featuring players you’d almost forgotten about, in acton 10 or 15 years ago.
And inside ten minutes, United had put the old boys to the sword thanks to an unexpected source – the left foot of Antonio Valencia.
Picking up a pass from Pogba, Valencia – back after a six-match lay-off with a hamstring injury - cut inside Josh Tymon and bent a shot inside the far post using the foot he normally only uses to stand upon.
United had already had a half-decent penalty shout turned down when Moritz Bauer wrestled over Martial – but then came a strange interlude where the Potters created three scoring chances.
Ireland – making his first Premier League start in almost three years – squandered the first two. The second from, a Xherdan Shaqiri lay-off, was begging to be buried but was fired wide.
Then after Ireland had royally mugged off Pogba in midfield, Crouch won a high ball and Eric Maxim Choupo-Moting had a close-range shot deflected over off Chris Smalling.
But this was all a false dawn for the Potters and United doubled their lead before the break with a classy goal.
Valencia won possession deep in the Stoke half and Lukaku cut back for Pogba who used his peripheral vision and a balletic turn to square a cheeky pass to Martial.
Martial’s first-time shot combined power, curl and accuracy to beat Jack Butland and that was more or less that as a contest.
David De Gea did have to make one sharp save from Shaqiri just before the break but without needing to go full throttle, United dominated.
Juan Mata missed a couple of choice openings before Lukaku twisted past Kurt Zouma and Kevin Wimmer to drill home left-footed.
Stoke were chasing shadows for long periods, drowned rats in a typical Mancunian squall, not exactly looking over the moon at the prospect of meeting their new boss.
United can look forward to a rather more welcome arrival when Alexis arrives at Carrington to join a soap opera which was once a glorious dynasty.
Weekend Round-up: Watch all the action from the Premier League games this weekend