It seemed it would be 12th time lucky for the Owls after the irrepressible Steven Fletcher plundered his 11th goal of the season.
But Chris Martin’s controversial penalty with eight minutes left denied Wednesday maximum points.
TV replays suggest Moses Odubajo was wrongly penalised for bringing down substitute Jack Marriott. If anything, Marriott appeared to drag the full-back down. Wednesday have every right to feel hard done by with the decision.
And to compound Odubajo's miserable evening, he was given his marching orders in the closing stages after two bookable offences.
Wednesday should have been out of sight after dominating the opening 45 minutes. They were quicker, stronger and technically superior in every department. Derby had no answer.
Sam Hutchinson ran the show in the centre, delivering a masterclass in screening the back four. His tackling and reading of the game was top notch.
Fletcher expertly fired the Owls ahead in the 23rd minute, sending an unerring left foot shot past Ben Hamer after Craig Forsyth carelessly gave the ball away to Barry Bannan. The midfield playmaker showed good vision and awareness to slip in Fletcher, who notched his sixth goal in his last five starts. It was a horrible defensive error by the Rams but Fletcher's finish oozed class and confidence.
Fletcher is in the form of his life and has already equalled his best ever seasonal haul for the Owls.
Asked what the secret has been to his success this season, the 32-year-old told The Star: "I’m just looking after myself at home and at the training ground.
“I do the gym twice a day and that lads always hammer me for it. I’m never out of the place.
“And I’m eating well too. I loved Irn-Bru when I was younger. That was my guilty pleasure.
“Obviously I don’t drink that any more. I’ll go back to it when I retire!"
Booed off at the interval, there was a strong response from the Rams after the break. The hosts, missing a number of senior players through injury, were much-improved, with Chris Martin and Jason Knight spurning opportunities to level things up.
There was greater intensity and purpose to the Rams play.
Nonetheless, Wednesday defended manfully and looked set to hold out on a bitterly cold evening in the East Midlands.
But Marriott's late spot-kick broke their hearts.
Indeed, the Owls could have left empty-handed but Marriott steered a header over from close range.
The draw means Wednesday missed the opportunity to move back into the play-off positions.
Garry Monk, the Owls boss, had challenged his players in the build up to the clash to put down a marker down this week. His team acquitted themselves well in the first period but they did not take their chances and Derby made them pay.