A first-half blitz, inspired by the excellent Ilkay Gundogan, saw City go into the break 4-0 up.
The Baggies managed to play out the last half-hour without conceding again, but it will be little consolation to Sam Allardyce whose side remain in deep trouble near the foot of the table.
West Brom were out of the blocks and in City’s faces for the first couple of minutes, launching throw-ins into a crowded box and looking dangerous enough to cause a few hurried hacks clear.
But having weathered the storm, City almost scored with the first attack as Bernardo worked himself space before finding Phil Foden who hit a low angled shot took a slight deflection and then was brilliantly fingertipped on to the foot of the post by Sam Johnstone.
Surely Johnstone, who almost single-handedly kept City at bay in the 1-1 draw at the Etihad last December, couldn’t again be our nemesis?
Three minutes later, he was beaten by a shot that left him rooted to the spot as Joao Cancelo picked out Ilkay Gundogan on the edge of the box and the in-form German shifted the ball to the left before striking a sublime shot into the bottom left-hand corner to put City ahead.
It was Gundogan’s seventh of an excellent season – already the best seasonal tally of his career.
City were moving the ball around with such fluidity, it seemed more goals were inevitable but when the second did come on 20 minutes, it was greeted in almost total silence and no celebration.
Bernardo collected the ball on the right and shortly after, the flag was raised for offside, but with no whistle to stop play, Bernardo picked out Cancelo on the edge of the box and the Portuguese curled a beauty into the top left corner.
With offside called, VAR then checked to see if Bernardo had been offside – but replays proved he marginally was onside – so the goal, which was a beauty, was awarded – perhaps the most socially distanced celebration ever?
And the first-half kept getting better for City as Gundogan made it 3-0 with another fantastic effort.
This time, the German midfielder created his own opportunity, winning the ball on the edge of the box, taking past a defender before drilling a low shot into that left-hand corner again.
It was sublime stuff from City, who have so many players playing at the top of their game just now.
And the best 45 minutes of the season was completed in first-half added time as Raheem Sterling spotted Riyad Mahrez on the right of the box and the Algerian instantly controlled the ball, shifted inside of a challenge before drilling a fierce drive into… you guessed it – the overworked left-hand corner of the net.
Bias apart, it was a joy to watch and as one celebrated fictional sports commentator might claim, ‘liquid football’.
City carried on where the first-half ended, with Rodri thumping he crossbar from 25 yards before the fifth of the evening came just before the hour.
City declared at five with the hard work done in the first-half.