The Premier League champions-elect gave Albion a football lesson as the world, Arsenal and Liverpool looked on.
Albion’s season effectively finished early last month in Rome and the Seagulls can’t go down or qualify for Europe.
A very rare Kevin De Bruyne header goal and two from Phil Foden gave City a very healthy 3-0 half-time lead.
Julian Alverez rolled a fourth into an empty net in the second half.
Albion appeared on terms with City until Foden released Kyle Walker down the line the speed of the England defender is astonishing and his cross was pinpoint for De Bruyne who looped a header over Jason Steele for apparently his first ever headed Premier League goal.
Albion almost answered from a Valentine Barco corner headed straight at Ederson by Lewis Dunk.
City doubled their lead in controversial circumstances Foden took an innocuous looking tumble just out side the area – he and De Bruyne stood over the ball and It was Foden who whipped it over the wall a sizeable deflection from Pascal Gross took it past Steele for 0-2
The third was a farce – Steele, Dunk, and Barco all involved in unnecessarily playing it out from the back the inexperienced Barco giving it away and Foden calmly slotting his seconds and City’s third.
It was over as contest although Albion had to big second half penalty’s as Gross and Pedro were both sent tumbling in the area
Alvarez made sure after Walker teased Steele out of his goal and the Argentine slotted into an empty netZ
Pedro had just to gain consolation before the end, but his shot from a cross from substitute Igor was too wide for his proximty to the goal.
Albion face Bournemouth down at the Vitaltiy on Sunday 28th – the Seagulls are one place and one point behind the Cherries.