Two goals either side of half-time put the Baggies firmly in the driving seat, before Sammy Robinson headed in from a corner to provide late consolation for Gareth Taylor’s youthful side.
After a cagey opening spell the visitors displayed electric pace on the counter attack and asked several questions of City’s backline, with forward Callum Morton forcing a string of saves from City ‘keeper Curtis Anderson.
City were comfortable in possession but Albion’s threat was constant, and Anderson’s resolve was finally broken on 32 minutes when Aram Soleman nodded in at the back post to break the deadlock.
The Blues responded well and twice went close to restoring parity when Ryan Corrigan fired over from close range before Henri Ogunby and Nabil Touaizi were both denied by the woodwork in a flurry of City chances on the stroke of half-time.
But West Brom punished City’s inefficiency in front of goal when Finn Azaz capitalised on an error at the back and slotted into the far corner to double the lead just before the break.
The visitors’ pace in the final third was a real handful for City and Azaz scored his second and Albion’s third on 55 minutes with a coolly-taken finish into the far corner.
City reverted to a back three in a bid to get back into the game, but their hopes were dashed on 65 minutes when Morton was brought down in the box by Eric García, with the striker converting from the penalty spot for a fourth.
A late push for a consolation saw City Felix Nmecha fire narrowly wide, before the midfielder turned provider for Sammy Robinson to head home from a corner in the dying minutes.
How they lined up
With Tommy Doyle away on England under-17 duty, City made five changes. Fisayo Dele-Bashiru replaced the midfielder while Nabil Touaizi started up front ahead of Felix Nmecha.
What it means
City slip to fourth in the under-18 Premier League north table after Everton beat third-place Liverpool to leapfrog Gareth Taylor’s side. Four points separate the top four in the league, with Manchester United top on 30 points.
City travel to Sunderland on February 24 before fellow high-flyers Liverpool are the visitors at the City Football Academy on March 3, with both games kicking off at 11.00am.