Walsall skipper Andy Butler headed a second-half winner at Molineux to shatter Wolves' 100% home record.
The visitors went close in a fiercely competitive Black Country derby when Craig Westcarr's free-kick hit the bar.
But Walsall got revenge for their JPT exit at Molineux a fortnight ago when, on 69 minutes, substitute James Baxendale hooked back Andy Taylor's cross for Butler to nod in the winner.
Walsall's only previous league triumph at Molineux came in August 1999, when Andy Rammell hit the winner in a 2-1 away victory, but they also won there in the League Cup in 1985.
Walsall sub Milan Lalkovic's free-kick then hit the post in the last minute.
Wolves had a first-half effort from Bjorn Sigurdarson, which flashed across the face of goal without anyone getting a touch, as did another similar effort from Bakary Sako, who also forced a good save out of visiting keeper Richard O'Donnell with a 30-yard free-kick.
O'Donnell then came to Walsall's rescue again on the stroke of half-time when he pushed out Kevin Doyle's header from Sako's corner as Wolves crashed to their first league defeat under new boss Kenny Jackett.
Walsall's second away win in four days lifts them up to seventh in League One.
Wolves, whose run of five straight league wins came to an end, remain third, having missed the chance to go back up into second.
VIEW FROM THE DRESSING ROOM
Wolves boss Kenny Jackett told BBC WM:
"After an even first half, we had all the territorial advantage in the second half but didn't create enough chances.
"I'm just disappointed that we lost to a set piece. Our marking on the far post wasn't good enough.
"Walsall just edged it and my task now is to make sure that we're better than that. Saturday's Shrewsbury game now becomes a very big game."
Walsall manager Dean Smith told BBC WM:
"It's a difficult place to come, against quality players, and we've restricted them to not many efforts. Our three-man midfield in particular were outstanding.
"We've made 2,500 Walsall fans very happy. But we have to keep reminding ourselves that it's only three points.
"We've now got two tough games coming up against Rotherham and Orient, who are both unbeaten, and that should help bring us back down to earth."
Live text and stats
Tuesday, 17 September 2013
13 Ikeme yellow card
11 McDonald yellow card (Griffiths 56)
14 Evans (Foley 57)
15 J Chambers
07 A Chambers
08 Mantom yellow card
11 Hemmings (Baxendale 65)
10 Westcarr (Sawyers 81)
24 Hewitt (Lalkovic 81)
Ref: RussellAtt: 22,240
Attempts on target
Attempts off target
90:00+5:37 The match has reached full-time.
90:00+5:10 Sam Ricketts takes the free kick.
90:00+4:55 Sam Mantom shown a yellow card.
90:00+4:51 Sam Mantom is adjudged to have handled the ball.
90:00+2:30 The ball is crossed by Bakary Sako.
90:00+1:10 Free kick taken by Romaine Sawyers.
90:00+0:57 Matt Doherty concedes a free kick for a foul on Andy Taylor.
90:00+0:44 James Baxendale takes the chance to get an effort at goal.
90:00+0:03 Shot from Milan Lalkovic from the free kick that hits the post.
89:59 Caution for Carl Ikeme.
89:22 Carl Ikeme is penalised for handball and concedes a free kick.
88:50 Corner from the right by-line taken by Adam Chambers.
88:19 Milan Lalkovic has an effort at goal.
86:47 Matt Doherty restarts play with the free kick.
86:43 The offside flag is raised against Milan Lalkovic.
82:51 Kevin Foley takes the chance to get an effort at goal and missed to the left of the target.
82:41 Corner taken by Bakary Sako.
82:31 The ball is sent over by Bakary Sako.
82:26 Clearance by Andy Butler.
82:20 Bakary Sako produces a cross.
80:51 Substitution Troy Hewitt leaves the field to be replaced by Milan Lalkovic.
80:27 Substitution Romaine Sawyers is brought on as a substitute for Craig Westcarr.
78:57 Header at goal by Matt Doherty misses to the right.
78:42 Corner taken by Bakary Sako.
78:26 Bakary Sako has an effort at goal.
78:06 Corner taken by Leigh Griffiths.
77:30 Shot by Sam Ricketts.
75:39 Shot by Leigh Griffiths went wide left of the goal.
74:29 Bakary Sako crosses the ball in from the free kick.
73:59 Foul by Andy Taylor on Matt Doherty, free kick awarded.
73:40 Clearance made by Sam Ricketts.
73:32 Adam Chambers delivers the ball.
70:52 Corner taken by Bakary Sako.
70:38 Kevin Doyle takes a shot. Blocked by Paul Downing.
69:52 Richard O'Donnell takes the free kick.
69:25 Unfair challenge on Andy Taylor by Matt Doherty results in a free kick.
69:02 The ball is crossed by Matt Doherty.
Correction - 68:07 GOAL - Andy Butler:Wolverhampton 0 - 1 Walsall Andy Butler slots the ball left footed into the goal. Wolverhampton 0-1 Walsall.
68:07 GOAL - Andy Butler:Wolverhampton 0 - 1 Walsall Andy Butler grabs a goal with a left foot finish. Wolverhampton 0-1 Walsall.
67:42 Andy Taylor crosses the ball in from the free kick.
67:11 Danny Batth challenges Andy Butler unfairly and gives away a free kick.
66:43 Shot by Sam Mantom. Carl Ikeme blocks the ball.
65:54 Paul Downing takes the free kick.
65:37 David Davis concedes a free kick for a foul on Andy Taylor.
64:38 Substitution James Baxendale on for Ashley Hemmings.
63:27 Header by Danny Batth goes to the left of the goal.
63:21 Corner taken by Leigh Griffiths from the left by-line.
63:07 The ball is sent over by Kevin Doyle.
61:26 Bakary Sako takes a shot and cleared the net.
59:49 Kevin Foley crosses the ball.
59:07 Leigh Griffiths sends in a cross.
58:32 Header by Kevin Doyle misses right.
57:37 Craig Westcarr delivers the ball.
56:15 Substitution (Wolverhampton) makes a substitution, with Kevin Foley coming on for Lee Evans.
55:49 Substitution Leigh Griffiths on for Kevin McDonald.
55:26 Free kick crossed by Craig Westcarr.
55:02 Unfair challenge on Craig Westcarr by Lee Evans results in a free kick.
54:23 Matt Doherty takes the free kick.
54:08 Free kick awarded for a foul by Andy Taylor on Bjorn Sigurdarson.
49:59 Paul Downing takes a shot and missed to the right of the goal.
49:43 Ashley Hemmings crosses the ball in from the free kick.
49:10 Kevin McDonald is given a yellow card.
48:59 Troy Hewitt fouled by Kevin McDonald, the ref awards a free kick.
48:30 Kevin Doyle sends in a cross.
47:36 Andy Taylor crosses the ball.
47:14 Free kick taken by Andy Taylor.
47:07 Ashley Hemmings fouled by Lee Evans, the ref awards a free kick.
46:26 Kevin Doyle takes a shot and went wide right of the goal.
46:19 The ball is delivered by Scott Golbourne.
45:01 The match restarts for the second half.
45:00+1:30 The ref blows to signal half-time.
45:00+1:24 Richard O'Donnell takes the free kick.
45:00+1:19 Kevin Doyle concedes a free kick for a foul on Andy Taylor.
45:00+0:58 Kevin Doyle has an effort at goal. Richard O'Donnell parries the effort to safety.
45:00+0:48 Corner taken by Bakary Sako from the right by-line.
45:00+0:26 The ball is delivered by Kevin McDonald.
44:54 Lee Evans restarts play with the free kick.
44:48 Foul by Adam Chambers on Lee Evans, free kick awarded.
43:15 Lee Evans has a direct shot on goal from the free kick. Richard O'Donnell makes a block.
42:23 Sam Mantom gives away a free kick for an unfair challenge on Kevin Doyle.
40:51 Sam Mantom takes a shot and goes harmlessly over the bar.
39:32 Header at goal by Danny Batth misses left of the target.
39:27 Corner taken by Lee Evans from the left by-line.
39:01 Bakary Sako has an effort direct from the free kick. Richard O'Donnell parries the effort to safety.
38:22 Ashley Hemmings gives away a free kick for an unfair challenge on Kevin McDonald.
36:25 Sam Mantom takes a shot.
32:24 Shot by Paul Downing missed to the right of the target.
32:15 Corner taken by Ashley Hemmings from the right by-line.
31:46 Corner taken by Craig Westcarr from the left by-line.
31:12 Andy Taylor restarts play with the free kick.
30:59 Kevin Doyle challenges Craig Westcarr unfairly and gives away a free kick.
30:31 Andy Butler makes a clearance.
30:23 The ball is sent over by Lee Evans.
28:59 Andy Taylor restarts play with the free kick.
28:44 Free kick awarded for a foul by David Davis on Sam Mantom.
28:03 The ball is crossed by Scott Golbourne.
27:37 Corner from the left by-line taken by Craig Westcarr.
27:17 Andy Taylor sends in a cross.
27:10 Paul Downing restarts play with the free kick.
26:57 Kevin Doyle is ruled offside.
26:17 Free kick crossed by Andy Taylor.
25:54 Foul by Matt Doherty on Craig Westcarr, free kick awarded.
25:15 Header by James Chambers misses right.
25:05 Corner taken by Craig Westcarr.
24:40 Free kick crossed by Ashley Hemmings.
24:14 Bakary Sako gives away a free kick for an unfair challenge on Troy Hewitt.
22:18 Bakary Sako takes a shot and went wide right of the goal.
18:15 A cross is delivered by Sam Mantom.
13:46 Scott Golbourne takes the free kick.
13:31 Bakary Sako fouled by James Chambers, the ref awards a free kick.
12:25 Richard O'Donnell restarts play with the free kick.
11:47 The assistant referee flags for offside against Kevin Doyle.
11:01 Sam Mantom produces a cross.
9:40 Ashley Hemmings takes a shot. Carl Ikeme safely holds on.
8:12 Craig Westcarr has an effort direct from the free kick hitting the bar.
7:22 Foul by Lee Evans on Sam Mantom, free kick awarded.
6:27 Troy Hewitt takes a shot.
5:08 Bjorn Sigurdarson takes a shot and missed to the left of the goal.
3:38 James Chambers makes a clearance.
Correction - 3:29 Corner taken by Lee Evans.
3:29 Corner taken by Kevin Doyle.
2:58 Clearance made by Andy Butler.
2:49 Bakary Sako crosses the ball in from the free kick.
2:30 Paul Downing concedes a free kick for a foul on Kevin Doyle.
1:55 The ball is delivered by Craig Westcarr.
0:00 The match begins.
Live text and data provided by The Press Association.
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