Albion's PL2 side were narrowly edged out by Southampton at Keys Park on Monday night.
Goals from Kami Doyle and Dom Ballard put the visitors firmly in control at the break, but Akeel Higgins' second-half effort gave Richard Beale's men hope of a turnaround.
But the Saints managed the closing stages well to prevent the young Baggies securing back-to-back victories.
Set pieces were an outlet Albion used in the early stages of their Premier League 2 encounter, and only last-ditch defending by the visitors stopped Ethan Ingram not once, but twice from heading in from Jamie Andrews' corner.
Still, Southampton provided the sucker punch in the opening ten minutes when Doyle curled in a free-kick from the edge of the box.
Ballard showed quick feet to win his team a spot-kick before the interval, forcing Aaron Harper-Bailey into bringing him down in the area, before the felled picked himself up to convert the resulting penalty.
2-0 down at the break, and although Reyes Cleary almost curled in a super effort before the end of the first 45, the Baggies couldn't find too many ways of hurting their south-coast counterparts.
Nevertheless, it was Beale's boys who got the game's next goal when Higgins was on his toes to pounce on a chaotic phase inside the area, which ended in the second-year scholar poking past Ollie Wright in the Saints goal.
Rico Richards saw a good shout for a penalty turned down, with Albion's No.10 clearly being hauled to ground by a Southampton defender. But the decision didn't go the home side's way, as they fell to defeat in Monday night's PL2 match.
Albion: Hollingshead; Ingram, Hall, Harper-Bailey, Humphries; Whitwell (Wangusi), Andrews ©️; Malcolm, R.Richards, Cleary; Higgins (Trialist).
Substitutes: Cisse, Nguepissi, M.Richards.