Wednesday emerged with a point from Pride Park but after dominating Derby for long periods – particularly in the first half – it could and arguably should have yielded three.
The Owls turned in a polished performance but were undone in the closing stages when Chris Martin converted a penalty to cancel out Steven Fletcher’s 11th goal of the season.
But the scoreline told only half the story as the visitors were in the box seat but failed to drive home their supremacy.
And to compound an ultimately frustrating night in the Midlands, Moses Odubajo saw an earlier yellow card upgraded to red in stoppage time.
The narrative was so different at the start as the Owls forced a flurry of corners and only some desperate Derby defending prevented an early opener.
Fletcher and Morgan Fox were denied by Craig Forsyth and Scott Malone respectively in goalmouth scrambles before Dominic Iorfa was inches away from connecting to Kadeem Harris’ cross at the back stick.
A goal was coming, though, and duly arrived on 23 minutes. Forsyth misplaced a ball out of defence into the path of Barry Bannan, who teed up Fletcher to finish first time with some aplomb from 20 yards.
The Owls were in dominant mood as Derby struggled to get to grips with the game. Any forward motion was met with a resistance that forced the hosts back and they might have gone further behind ahead of half time as Jordan Rhodes and Sam Hutchinson went close.
Derby needed a boost and almost provided it moments after the resumption when Duane Holmes got to the byline and found Chris Martin inside the six-yard box but the striker’s header was too high.
The Rams showed an intensity missing from the opening period – Jason Knight tried his luck with a daisycutter from range that Cameron Dawson watched past the post.
Fletcher forced Ben Hamer into action at the other end from a low drive before the second half pace set by Derby began to wane.
Manager Phillip Cocu made a double change on the offensive in a bid to spark his side but Wednesday were resolute and well organised.
The Rams saw more possession as the clock counted down and were rewarded with eight minutes to go from the spot.
Odubajo tangled with substitute Jack Marriot, the referee had no hesitation, and Martin sent Dawson the wrong way from 12 yards.
Then, right at the last, Odubajo impeded Malone in full flight and was sent off to conclude a brief passage of play to forget for the defender, who will sit out the trip to Nottingham Forest on Saturday as a result.
Wednesday: Dawson, Odubajo (S/O 90), Iorfa, Lees, Fox, Harris (Murphy 61), Hutchinson, Bannan, Reach, Rhodes (Nuhiu 71), Fletcher (Luongo 78)