Wednesday slumped to their fourth home loss on the trot as they went down 3-1 to Brentford on Tuesday.
Michael Spillane opened the scoring and although Rob Jones swiftly levelled, further strikes from Jeffrey Schlupp and Sammy Saunders condemned the Owls to defeat.
Wednesday got off to the worst possible start when the Bees stormed into the lead after just three minutes. Nathan Byrne swung over an accurate corner and Spillane rose high to bury a firm header into the back of the Kop net.
The Owls were stung into life and responded with a Gary Madine header that whizzed over the bar after a fine cross from Isaiah Osbourne.
Jones then had an on-target effort deflected wide before the on-loan defender buried a glancing header past Trevor Carson on 12 minutes from the resulting corner to level the score.
But just as Wednesday seemed to have their tails up, Brentford promptly restored their advantage after 18 minutes.
Byne again played a key role down the right flank, this time conjuring a delightful feed that Schlupp nodded home from close range.
The Owls were dealt another blow when goalscorer Jones was withdrawn following a clash of heads and Jon Otsemebor came on for his first taste of action since early January.
Darren Potter curled a teasing free kick over the bar as Wednesday sought another route back into the contest but Brentford were clearly buoyed by their early double and the home side struggled to prise open the Bees' rearguard.
Wednesday were in need of a breakthrough soon after half time if they were to haul their way back and almost did exactly that.
Madine forced a fine save from Carson, who could only parry to Gary Teale, and the Scot's acrobatic effort from 12 yards was cleared off the line by Craig Woodman.
Gary Megson made a double substitution just before the hour, with Clinton Morrison and Jermaine Johnson coming on for Paul Heffernan and Darren Potter.
Johnson looked lively in possession and was the Owls' most likely threat and only a brave block by Karleigh Osborne prevented the Jamaican striking an equaliser.
Johnson again went close 12 minutes from time after tricking his marker but his daisycutter across goal fell just the wrong side of the post.
But it was Brentford that had the final word, with substitute Saunders finding the net with a well-placed free kick to leave the Owls looking nervously over their shoulders at the wrong end of the League 1 table.
Owls: O'Donnell, Buxton, Batth, Jones (Otsemobor 25), Spurr, Teale, Osbourne, Potter (Johnson 58), O'Brien, Madine, Heffernan (C Morrison 58)
Unused substitutes: Nicholls, M Morrison, Miller, Sedgwick
Brentford: Carson, O'Connor (Tudor-Jones 69), Woodman, Bean, Balkestein, Spillane, Wood (Saunders 63), Grabbam, Osborne, Schlupp (Bignall 46), Byrne
Unused substitutes: Moore, Weston, Wright, Legge