Substitute Luke Little's late goal proved only a consolation as the Saddlers' Under-18s fell to a 2-1 home defeat by in-form Wigan.
Wigan were totally dominant in the first half, racing into a two-goal lead.
The Saddlers, who were without a few regulars, battled in a frustrating stop-start game which the referee struggled to keep on top of, but came away with nothing.
Left wing-back Cody Fisher had to be brought off for Debert Massamba in the first few minutes of the game after colliding into the barrier off the pitch when trying to keep in a loose pass.
Wigan had a lot of the ball in the Walsall half and scored from their first real chance on 28 minutes, Mwiya Malumo headed a cross beyond home keeper Brandon Ganley.
The Latics then made it 2-0 just before the break courtesy of a screamer from Lang. The midfielder picked the ball up deep in the Walsall half and unleashed a powerful shot that flew in via the post.
Half-time: Walsall 0-2 Wigan
Graham Biggs' side came out much more positive in the second half and began to carve out some chances.
Ethan Freemantle had a couple of decent opportunities, first seeing a diving header tipped round the post before an effort from a cut-back went just wide.
Then, Lezion Cela's brilliant crossfield ball picked out the run of Will Shorrock, who used his quick feet to give himself a yard of space but his shot was crucially blocked.
Walsall continued to press, with Freemantle hitting a first-time volley on the turn which was well held by Latics keeper Jordan Perrin.
As the game entered its final moments, the Saddlers threw everything at Wigan to try and claw their way back into the game.
And they were given a glimmer of hope deep into added time when Perrin fumbled a cross straight to substitute Little, who tucked the ball home.
However, it proved to be the home side's final opportunity, with Walsall unable to carve out another chance before the referee blew for full-time.
Full-time: Walsall 1-2 Wigan
Team: Ganley, Mason, Fisher (Massamba 8'), Kendrick, Vann, Cockerill-Mollett, Cela, Maddocks (Friel 87'), Freemantle, Cairns (Harvey 72'), Shorrock (Little 83').
Subs not used: Caswell