Second-half goals from Reece Flanagan, Zeli Ismail and Luke Leahy saw the Saddlers come from behind to beat West Brom U21s in Checkatrade Trophy Northern Group E.
Rayaan Tulloch put the young Baggies ahead in first half injury time but Flanagan equalised nine minutes into the second half with a 20-yard strike.
Ismail volleyed the hosts in front on 67 minutes and Leahy’s cross-shot rounded off the scoring ten minutes from time.
A much-changed Saddlers team dominated a first half in which chances were few and far between.
Kieron Morris was first to threaten on 15 minutes as he jinked past two players before testing Baggies custodian and captain Alex Palmer low down at his near post.
Daniel Agyei was next to go close, the Burnley loanee holding off a couple of defenders and bending a left-footed effort a whisker wide from inside the area.
Amadou Bakayoko and Maz Kouhyar each fired over from long range as the hosts struggled to break down a well-organised Albion defence.
On a rare Baggies attack, Alex Bradley drove infield and spotted Walsall keeper Liam Roberts off his line but his attempted lob sailed harmlessly over.
The home side could have taken the lead four minutes before the break but Palmer got down well to tip Kouhyar’s 20-yard strike wide after good play from Agyei.
Instead it was the visitors who broke the deadlock in first-half injury time, Aram Soleman skipping past Kouhyar and delivering a low cross which Rayaan Tulloch side-footed home from close range.
The Saddlers weren’t behind for long, though, equalising on 54 minutes when Flanagan checked back onto his right foot and fired a powerful 20-yard drive into the corner.
Only the woodwork prevented Walsall from going in front nine minutes later as Liam Kinsella’s excellent right-wing centre was headed onto the bar by Morris from six yards.
Jon Whitney’s men continued to press and went ahead with 17 minutes remaining, Morris standing up a cross for Ismail to volley into the net.
And the home side made sure of the win ten minutes from time as Leahy’s left-wing cross caught out Palmer at his near post.
The result puts Walsall top of Northern Group E, ahead of second-placed Shrewsbury – 3-2 winners in their first match at holders Coventry – on goal difference.
Team: L Roberts, Kinsella, Guthrie, K Roberts, Leahy, Ismail (Shorrock 83’), Flanagan, Kouhyar, Morris (Sangha 90’), Agyei (Candlin 75’), Bakayoko.
Subs not used: Gillespie, Devlin, O’Sullivan, Mason.