City's seven game unbeaten run came to an unfortunate end at the Britannia Stadium.
Ricardo Fuller's double wasn't enough as the visitors hit four to end the Potters' good run of form.
The Jamaican fired the hosts in front after 11 minutes, but Jermaine Johnson and Marcus Tudgay responded quickly to put Wednesday ahead.
Fuller equalised in the 40th minute, before Tudgay and Deon Burton secured an undeserved three points for the visitors late on.
Tony Pulis recalled Jon Parkin to the starting line up ahead of the match with Mamady Sidibe absent, while Gabriel Zakuani returned for the injured Stephen Wright.
The match started and former City star Graham Kavanagh was first to test City's waters after just one minute, but his rasping 25-yard drive flew well wide.
The visitors won the first corner of the game on four minutes, after Francis Jeffers saw his shot deflected wide.
But the Potters rearguard stood firm to clear the danger.
A trademark Rory Delap long throw in caused problems in the Owls 18-yard box, with Andy Wilkinson lashing just over form 15-yards.
Fuller set off on a mazy run down the right flank before cutting in and whipping a dangerous ball across the box, which just evaded Richard Cresswell.
A quick counter attack from Wednesday saw Glenn Whelan tee-up Kavanagh with a clever ball, but the on loan Sunderland man fired just past Steve Simonsen's right hand post.
Pulis' side immediately responded with a chance of their own. Lawrence whipped in a curling free kick which Shawcross connected with but a defender flicked the ball away from danger.
An exciting start to the game saw the hosts take the lead through the in form Fuller after just eleven minutes.
The Jamaican international out paced Richard Wood before exquisitely turning and holding off a second defender before slotting the ball under Lee Grant and in to the bottom corner.
However, the lead lasted just five minutes as former Bradford star Johnson unleashed a rasping 20-yard strike which flew in to the roof of the net.
City were rattled and just minutes later Brian Laws side took the lead, Marcus Tudgay's shot smashed the post, before Jeffers picked the ball up and brilliantly picked his fellow striker who made amends and headed home.
Kavanagh then attempted to embarrass Simonsen from the half way line, but the City keeper caught the ball comfortably.
Shawcross went in for a challenge with Jeffers on the half hour mark, and the former Arsenal man looked in some pain, and was subsequently stretchered off with former City loanee Deon Burton coming on as his replacement.
Zakauni linked up well with Lawrence but his teasing cross was flicked away just as Parkin was arriving to head home.
Burton O'Brien skipped past Shawcross after Kavanagh picked him out, but his shot agonisingly whipped inches past the post.
City levelled the scoreline in the 40th minute, with Fuller finding his second of the game and sixth of the season.
A poor pass back to Grant saw Fuller power forward before heading the ball past the outstretched Grant and in to the net, despite the efforts of Wood, who valiantly tried to hack the ball away.
The Potters pushed forward in the final minutes of the half but couldn't find a way through the defence.
The start of the second period saw the visitors bring on Richard Hinds for captain Lee Bullen.
City created the first chance of the half as Parkin latched on to a Fuller knockdown, but his shot flew over the bar, and in to the Boothen End.
Eustace spectacularly fired home from 30 yards, but the referee had already blown for an infringement by Parkin moments earlier.
'The Beast' was brought off after 60 minutes, and Peter Sweeney came on to add some fresh legs to the City side.
And the bosses decision could have proven to be a masterstroke had the Scottish winger been able to fire his powerful drive just a meter either side of Grant on 65 minutes.
Fuller, who was outstanding, danced his way past two defenders on the right wing before picking out Cresswell, who flicked the ball goalwards, but Grant gathered on the line.
Eustace was next to react to another piece of brilliance by Fuller, but after the Jamaican had centred, he fired over the bar with a defender hot on his heels.
Against the run of play the visitors snatched a late goal to make it 3-2.
Kavanagh's out-swinging corner was headed downwards by former Derby star Tudgay and the ball bounced in to the back of the net.
Salt was rubbed in to City's wounds two minutes from the end as substitute Burton fired home from 20-yards, via a massive deflection.
CITY (4-4-2): Simonsen, Zakuani, Shawcross, Matteo (c), Wilkinson; Lawrence, Eustace, Delap, Cresswell; Parkin (Sweeney 63), Fuller. Subs: Hoult, Buxton, Dickinson, D.Phillips.
WEDNESDAY (4-5-1): Grant, Bullen (c) (Hinds 46), Wood, Spurr, M. Johnson; J.Johnson (Sodje 88), O'Brien, Kavanagh, Whelan, Tudgay; Jeffers (Burton 34). Subs: Lunt, Esajas.


















