On-loan Chris Cornes scored his third goal in four days midway through the second half to give Port Vale victory.
Chris Birchall gave Vale an early lead, but Walsall's teenage debutant Ishmel Demontagnac crossed for Sam Collins to equalise shortly afterwards.
Demontagnac then bent in a superb shot to put the visitors ahead.
Vale were back on level terms soon after the interval when Gary Mulligan pounced at close range before Wolves striker Cornes grabbed the points.
Port Vale: Goodlad, Abbey (Rowland 21), Pilkington, Collins, Bell (Innes 74), Birchall, Sonner, Cummins, Cornes (Clarke 89), Paynter, Mulligan.
Subs Not Used: Brain, Cardle.
Goals: Birchall 8, Mulligan 55, Cornes 72.
Walsall: Ruddy, Wright, Westwood, Gerrard, Fox (Bennett 58), Standing, Smith, Osborn, Gillett (Kris Taylor 64), Demontagnac (Larrosa 65), Leitao.
Subs Not Used: Kinsella, Gilmartin.
Goals: Collins 24 og, Demontagnac 36.
Ref: S Mathieson (Cheshire).