Albion were defeated at Portsmouth on Saturday afternoon.
Strikes from Conor Chaplin, Millenic Alli and Ebou Adams ensured all three Sky Bet Championship points for the hosts at Fratton Park.
The home side made the brighter start to proceedings. Forward Chaplin had two opportunities to notch in the early stages, before eventually grabbing the opener, as he drilled home a cutback.
Portsmouth scored a second not long after, Andre Dozzell opened up the visiting back-line, leaving Alli the opportunity to stroke into the net and double their lead.
Despite three changes from Eric Ramsay at half-time, it was the hosts who once again made the opening stages of the half count - this time midfielder Adams found space to bundle a third home.
Mikey Johnston tested Portsmouth goalkeeper Nicolas Schmid with a curling effort afterwards, but otherwise, the Baggies were left empty-handed on the South Coast.
Albion: O’Leary; Mepham, Phillips (Styles 46’), Taylor; Iling-Junior (Maja 46’), Molumby (Mowatt 73’), Diakité, Imray (Gilchrist 46’); Price, Heggebø, Johnston (Wallace 63’).
Substitutes: Griffiths, Dike, Whitwell, Bostock.
