Albion's youngsters fell to defeat in their PL2 encounter with Blackburn Rovers on Monday evening.
The Baggies had looked set to secure their first win of the campaign in the competition after going 2-0 up through Rio Parmar and Harry French, but for a second-half blitz from the hosts - who showed their clinical side in the second '45.
It was Rovers who would threaten first through Harvey Higgins - his header drifting wide of the mark, before Alfie Maughan tested the hosts' goalkeeper with an ambitious free kick, and the home No.9 again spurred another opportunity as he beat Louis Brady to a cross.
Parmar almost netted what would've been a stunning solo goal on 26 minutes, going on a mazy run before seeing his strike on goal deflected out of play.
Albion were in the ascendancy soon after, and it was the attacker who would make the breakthrough. He saw the goalkeeper save his initial strike after darting into the box, but he was there to scramble home the follow-up and hand his side the advantage just after the half-hour mark.
French then doubled the lead just a few minutes later, bundling home a pinpoint Maughan cross - giving the visitors a healthy advantage heading into the half-time break.
That cushion didn't last long into the second half, however, with Isaac Dunn sending Brady the wrong way from the penalty spot, and the leveller came a few minutes later with the home skipper netting his second of the evening, taking aim and finding the bottom left corner from long-range to restore parity in Lancashire.
With the hosts buoyed, a third strike came with 20 minutes to play - Higgins getting in between Brady and Noah DuPont before slotting into an empty net after an unfortunate double deflection.
As Albion pushed for a way back into the game, they risked being hit on the counter-attack - and De Neve was the man to do that, netting Rovers' fourth of the evening, leaving the visitors with little hope of an unlikely comeback, and winless in PL2 after five matches played.
Albion: Brady; Maughan (Mohammed 63'), DuPont, Shaw (Perkins 86'), Letlat; Crowther (Lucas 63'), Blackshields, Parmar, Dlamini (Francis-Caesar 63'); Dexter (Seven-Seven 76'), French.
Substitutes: Rutter.
