The Belgians took an early lead after 5 minutes, with a rasping shot from 20 yards out from Nicky Van Den Abbeele.
Wales got back on level terms on half an hour, with a well taken volley from Ellie Curson on the edge of the penalty area.
The second half was nip and tuck but a defensive lapse on 70 minutes let substitute Liesbet Vanhoomissen in for a tap-in that proved to be the match winner.
Honours equal after the two games, Wales having won the first match 1-0, but good match practice for both sides.
Wales: Katy Maddock (Gemma Jackson, 41), Rhian Clevereley (Lauren Hancock, 57), Katie Williams, Sadie Mansell, Cherie Bessant, Danielle Oates, Angharad James, Hannah Keryakoplis, (Demi Edwards, 74), Ellie Curson, Chelsea Green (Ashleigh Harries, 57), Shanelle Edwards (Chloe O'Connor, 48).
