Goals either side of half time gave Cardiff victory over Wednesday in a game of few chances at Hillsborough.
The Owls matched the league leaders in most areas of the pitch but the Bluebirds had the edge in front goal and that proved the difference.
Don Cowie’s opener right on the stroke of half time was a turning point after a first half that saw the two sides largely cancel each other out.
Matthew Connolly then put the game to bed with a headed goal just after the hour.
It was an important match for both sides, the Owls looking to keep their distance from the drop zone and continue the form that saw them defeat promotion-pushers Leicester last week.
Meanwhile, table toppers Cardiff were hoping to further their lead at the summit with a win.
The Owls started brightly and Jeremy Helan forced an early save from Cardiff goalkeeper David Marshall.
There were few clear cut chances for either side for the majority of the opening 45 minutes but it was the Welsh outfit that broke the deadlock on 45 minutes.
A Craig Bellamy corner fell to Cowie, who fired a deflected shot past Chris Kirkland to give the visitors the advantage at the break.
With the hour mark approaching, Dave Jones switched to a 4-4-2 formation. Gary Madine replaced Danny Pugh and took up position alongside Leroy Lita in attack.
But the change of formation was to no avail as the Bluebirds doubled their advantage on 65 minutes.
Peter Whittingham’s free kick found Connolly unmarked in front of goal and his header left Kirkland with no chance.
The Owls almost hit back immediately when Miguel Llera’s goal-bound free kick forced a stunning fingertip save from Marshall.
A second free kick from Llera brought another save out of Marshall on 80 minutes and the Spaniard’s set pieces seemed to be Wednesday’s biggest threat as they looked to salvage something from the game.
But the Bluebirds’ defence held firm despite some late pressure and the visitors took all three points back to Cardiff.
Owls: Kirkland, Buxton, R Johnson, Gardner (c), Antonio (Maguire 78), Helan (J Johnson 67), Pugh (Madine 55), Lee, Lita, Prutton, Llera
Unused substitutes: Bywater, Taylor, Semedo, McCabe
Cardiff: Marshall, Taylor, Whittingham (Conway 84), Cowie, Connolly, Gunnarsson, Helguson, Barnett, Campbell, Nugent, Bellamy
Unused substitutes: Lewis, McNaughton, Kim, Smith, Gestede, Mutch