
Taking place at Newport County's Rodney Parade, Matty Jones' side were looking to earn what would have been their first win in two outings, but the young Dragons were on the receiving end of a humbling defeat.
Scoring some seven goals without reply, Belgium's first arrived with just four minutes on the clock when Jorthy Mokio hit the back of the net.
Mokio was joined on the scoresheet by Lucas Stassin (2), Romeo Vermant, Diego Moreira, Norman Bassette, and Noah Adedeji-Sternberg as Wales, who saw Ed James red carded after sixty-two minutes, were simply unable to respond.
Cox, who has made just four Walsall appearances, the most recent coming in early September as the Saddlers defeated Shrewsbury Town in the EFL Trophy, played the full ninety minutes, but will be far from happy with the result.