Another pulsating affair saw City beaten 3-2 in a game that was so nearly won not once but twice at Hillsborough.
Having led 2-0 at half-time thanks to a Tammy Abraham brace, the contest hinged on three mad minutes around the hour mark.
By this point 2-1 down, Wednesday were reduced to ten men and Lee Tomlin stepped up to seemingly make the game safe from the penalty spot.
When Tomlin’s kick struck the post, the hosts broke away and Gary O’Neil was dismissed for a second bookable offence in a matter of seconds.
Barry Bannan duly equalised after Steven Fletcher had already pulled one back and Kieran Lee struck the killer blow at the death.
Lee Johnson made three changes to his side, which is not uncommon in a three-game week.
In came Josh Brownhill, Marlon Pack and Callum O’Dowda, with Scott Golbourne, Bobby Reid and Luke Freeman the men replaced as Joe Bryan dropped to left-back.
Elsewhere, Korey Smith was among the substitutes – his first involvement in a matchday squad for five months – but new signing Gustav Engvall remained sidelined by injury.
The travelling City fans may have been fearing the worst when a torrential downpour half an hour before kick-off forced a 15-minute delay, but the pitch was in fine fettle by the time the action got under way.
A subdued start to proceedings, possibly due to a wet surface that saw bouncing balls skid away from their intended recipients, may have played into City’s hands as it quietened a previously boisterous home crowd.
Slowly but surely the visitors began to take control. The corner count started to climb, before Tomlin fired the first warning shot after 17 minutes.
When Callum O’Dowda’s initial cross was only half-cleared, Tomlin picked up the pieces and took aim on the half-volley with a deflected effort that had Kieren Westwood scrambling and relieved to watch it past the post.
Adam Reach’s 30-yarder that dribbled well wide in reply was symbolic of how City were getting the better of their hosts.
Better was to follow from a Wednesday point of view when Bannan’s floated cross was nodded back by Reach and blasted over by Fletcher, but former Hillsborough stopper Richard O’Donnell remained untroubled.
It had not been a spectacle to match the thriller at Rotherham United three days prior, but City had got a foothold in the game and took the lead after 33 minutes.
From another corner, O’Neil’s delivery was headed straight back out to the midfielder, whose second cross from the right was powered home by Abraham with a ruthless header from eight yards.
The opening goal briefly brought the home team to life but that man Abraham was in the right place again to double City’s lead six minutes later.
The teenage striker may take the plaudits, taking his tally to eight goals in nine games, but Brownhill was at the heart of it.
The busy midfielder picked up possession just inside the Wednesday half and immediately set about going forward.
After trading passes with Tomlin, space opened up for the youngster to try his luck with a 25-yard thunderbolt.
It proved too hot to handle for Westwood, who did well to stop the shot but could not parry the ball to safety. Instead it looped into the air invitingly for Abraham to nod in from close range.
Again Wednesday responded with a bit of pressure, pinning City back late in the half, but Fletcher’s shot on the turn was well blocked and the visitors could reflect on a job well done at the interval.
Home boss Carlos Carvalhal would have been expecting an improvement after the break and he was not disappointed.
There was fire in the bellies of his players, as Lee surged into the box and brought out the best in O’Donnell at his near post.
From the ensuing corner, Fletcher rose highest to plant an unstoppable header into the bottom corner and halve the deficit.
But the biggest moments in the match were still to come and duly arrived in the space of three bizarre minutes.
First Abraham’s disguised pass sent Pack into the box, who in turn was sent tumbling by last man Hutchinson.
Referee Darren Bond sent the Wednesday defender off and Tomlin had the chance to put City 3-1 up with a man advantage, only to strike the base of the post from the spot.
Amazingly, with the ball still in play the hosts broke quickly and Bond immediately found himself evening up the numbers when O’Neil was unfairly given his marching orders despite winning the ball on the halfway line.
With 18 minutes remaining, Smith entered the fray to make his comeback but was powerless to prevent Bannan drawing Wednesday level three minutes later, as the midfielder took aim from 30 yards with a shot so well struck O’Donnell got a glove to the ball but could not keep it out.
With the home supporters baying for more, City were forced to dig in and looked set to earn a point until Lee pounced deep into stoppage time.