Wednesday did everything but score in a dominant second half display but the Owls' failure to take their chances meant they suffered a fourth consecutive Championship defeat.
Cameron Jerome's 19th-minute goal did the damage to enable Cardiff to complete a league double over the Owls which this performance scarcely merited.
The Bluebirds had been the only team who really gave Wednesday the runaround upon their return to the second tier of league football in 2005, netting three goals in a one-sided first half at Hillsborough. The pacy Jerome had scored twice on that occasion and Paul Sturrock's selection reflected his threat, with three centre-backs employed to start for the first time this season.
For good measure, Jerome was on the receiving end of a couple of hefty challenges in the opening five minutes. But, while Wednesday's reshaped team started the game well and restricted the supply line to the 19-year-old from open play, the frontman instead took it upon himself to exact his revenge from a simple corner. Jason Koumas' inswinging delivery went through a forest of bodies and Jerome flicked a backheeled shot home from close range for his 18th goal of the season.
For a while the goal seemed to knock Wednesday out of their stride as City proceeded to dominate possession. But Chris Adamson's goal was not really tested while, on the half hour, Chris Brunt broke forward to send a 25-yard effort just wide.
As half-time approached, the Owls nearly snatched a leveller through Marcus Tudgay, whose overhead kick was scrambled wide by Neil Alexander. When the visitors continued to apply pressure from the resultant corner, Tudgay will have felt he should have done better than to send a mishit shot straight at the keeper.
If that was a good chance then there were two glorious opportunities that came Wednesday's way around the hour mark. First Tudgay escaped down the left and sent an inch-perfect cross to the far post but Deon Burton's volley looped over the bar. Then Glenn Whelan drove over when well-placed on the edge of the box.
As the Owls continued to press, Burton, showing he had lost none of his confidence, shot wide from 25 yards after creating the opening for himself. Another golden chance came 13 minutes from time when Brunt's corner landed at the feet of Lee Bullen, whose close range shot was cleared off the line by Darren Purse.
Two minutes later, Purse was extremely fortunate not to be punished for a rash penalty area challenge on Yoann Folly. Incensed Wednesday players surrounded referee Lee Probert after he waved play on, to no avail.
Chances came and went for Whelan and Tudgay in the final ten minutes while Cardiff striker Steven Thompson rippled the side netting in a rare break forward. Wednesday knew it wouldn't be their day when Leon Best's last-minute header was clawed away by Alexander on the line. Shortly afterwards, the final whistle signalled that City had somehow survived to send Wednesday back to England empty-handed.
Cardiff (4-4-2): Alexander; Ardley, Purse, Cox, Barker; Koumas, Whitley, Scimeca, Ledley; Jerome, Thompson (Ndumbu 90+1). Subs: Margetson, Weston, Loovens, Ferretti.
Wednesday (3-5-2): Adamson; Collins, Simek, Coughlan; Bullen, Whelan, Folly, Brunt (Best 77), O'Brien; Burton, Tudgay. Subs: Kirby, Spurr, Rocastle, Partridge.
Referee: L Probert
Attendance: 11,851
