LUKE Moore extended his free-scoring pre-season run as Albion fought back from two goals down.
The Baggies had a mountain to climb when sloppy defending allowed Dwayne Mattis and Matt Richards to net inside two minutes on the stroke of half-time.
But Moore halved the deficit with a well-taken third goal in four games in the 61st-minute.
The ex-Villa striker then won an 87th-minute penalty, which sub Craig Beattie converted - his third pre-season strike.
Albion enjoyed plenty of possession and Scott Carson's goal had barely been threatened before Walsall's double blast.
The visitors posed much more of a threat after the break and were full value for their two goals.
The fightback was just reward for the Baggies' terrific 2,493-strong following, who outnumbered the home fans.
Albion were handed a couple of pre-match fitness boosts, with Graham Dorrans able to make his pre-season bow after a foot injury and Simon Cox returning after a two-game absence with an ankle problem.
Youssouf Mulumbu and Beattie dropped to the bench while Leon Barnett and Dwayne Samuels came in for Shelton Martis (ribs) and Gianni Zuiverloon respectively.
Carson had to come to Albion's rescue with only 50 seconds on the clock. After the visitors lost possession deep in their own half, the ball fell perfectly to Richards whose fierce 15-yard drive was brilliantly kept out by the England keeper's legs.
The Saddlers were certainly well up for this mini-derby and Samuels had to make a brave headed clearance to deny Troy Deeney a clear chance from Richard Taundry's centre.
Albion gradually stamped their authority on the game and Moore fashioned a chance for himself out of nothing when he spun his marker from Robert Koren's lay-off before firing straight at Clayton Ince from just inside the box.
On 12, terrific Baggies inter-play resulted in Cox threading Koren through. The Slovenia skipper got to the ball just before Ince, who took him out, but his weak prod goalwards was cleared and no penalty was given.
Albion were dominating possession as the half reached its midpoint but failed to make the most of two corners, with Cox and Marek Cech seeing their centres drift straight to Ince.
On 25, Walsall gifted Roberto Di Matteo's men possession and Koren drove forward to play in Moore, whose first-time 20-yard drive again flew straight at Ince.
Walsall were struggling to get anywhere near Carson's goal and Taundry and Deeney were both off target with efforts from distance.
Albion were stroking the ball around with real confidence at times and Cech and Dorrans combined to tee up Koren just inside the box, but the ex-Lillestrom ace was disappointed to see his right-footed prod sail straight at Ince.
The Baggies were keeping possession for fun and, after another long spell of keep-ball, Koren recorded the shot of the game thus far, seeing a ferocious 25-yard drive pushed away superbly by Ince.
But despite Albion's superiority, they were finding it hard to get behind Walsall's rearguard, with the Saddlers happy to keep plenty of men behind the ball.
And, against the run of play, the hosts turned the game on its head by netting TWICE in as many minutes.
On 44, Taundry's hanging cross was headed back into the danger-zone by Richards and Mattis neatly tucked the ball inside the far post.
Albion had barely gathered their thoughts when it was 2-0.
The Baggies defence was at sixes and sevens when Alex Nicholls bundled his way into the box.
Samuels stopped him in his tracks with a last-ditch challenge but the ball broke to Richards who curled sublimely inside the top right-hand corner from 20 yards.
Carson, a passenger for most of the half, had no chance with either goal.
Di Matteo made one change at the break, with Mulumbu coming on for the excellent, but exhausted, Dorrans.
Albion opened the half with two long-range efforts from Koren and Chris Brunt, but neither troubled sub keeper Rene Gilmartin's goal.
The Baggies slowly got on top and Cox came within a whisker of connecting right in front of goal with Brunt's delicious right-wing centre.
Di Matteo rang three more changes on 58, with Cox, Samuels and Barnett making way for Beattie, Zuiverloon and Abdoulaye Meite.
Walsall recorded their first effort of note since the interval on the hour mark when sub Josh O'Keefe dragged his 15-yard shot wide of the far post.
But Albion hit back on 61.
Brunt's terrific right-wing centre dissected the two Saddlers centre-halves and Moore chested the ball down in the box before clinically firing home.
Albion created a great chance to level six minutes later when Zuiverloon threaded in Koren down the right.
The midfielder pulled the ball back to the unmarked Brunt who wastefully smashed over the bar from 15 yards.
Moore then went close when his instinctive header from Cech's corner, which had been flicked on by the commanding Jonas Olsson, flashed wide.
It was all Albion now and the lively Moore saw a 20-yard drive deflect off a Walsall defender and screw just wide.
Then, from a Filipe Teixeira corner, Beattie went even closer when he bundled the ball into the side-netting from Meite's knock-down.
The Scotland international tried his luck with a long-range volley on 80 but his effort flew straight at Gilmartin.
But Albion finally made the breakthrough three minutes from time. Moore was brought down by Gilmartin after racing onto Teixeira's throughball and Beattie confidently despatched the spot-kick.
WALSALL (4-4-2): Ince (Gilmartin HT); Weston (Westlake HT), Hughes (C), Smith (Roberts 67), Vincent; Taundry (Geddes 78), Bradley (Davies HT), Mattis (O'Keefe HT), Richards (Adkins 62); Deeney (Jones HT), Nicholls (Parkin HT). Sub not used: Till.
ALBION (4-4-2): Carson; Samuels (Zuiverloon 58), Barnett (Meite 58), Olsson, Cech; Koren (Valero 83), Greening (C) (Kim 83), Dorrans (Mulumbu HT), Brunt (Teixeira 67); Cox (Beattie 58), Moore. Sub not used: Kiely (GK).
GOALS: WALSALL - Mattis (44), Richards (45+1). ALBION - Moore (61), Beattie (87 pen).
BOOKINGS: None.
REFEREE: A Penn.
ATTENDANCE: 4,358 (2,493 Albion fans).
ALBION STARMAN: Graham Dorrans.
PIC: SPOT ON...Beattie equalises at the Banks's Stadium
