The Owls’ battle against the drop took a dent as Middlesbrough emerged 2-0 winners at the Riverside Stadium.
Michael Ihiekwe’s own goal separated the two at the break and Isaiah Jones doubled the lead in the second half.
In truth, it could have been worse as Boro created a raft of opportunities before Sam Greenwood missed a late penalty.
But Wednesday came so close to a dream start when Marvin Johnson’s angled hit shaved the outside of the post after a fine Will Vaulks pass split the Boro backline.
The hosts, though, promptly took control. Lewis O’Brien had a low shot deflected wide and the influential Greenwood saw his free-kick whistle just over the bar.
In a rare Owls foray upfield, Anthony Musaba was a whisker away from connecting to Bailey Cadamarteri’s cross but the Teessiders’ dominance soon resumed.
They squandered a gilt-edged chance when Greenwood sent in a perfect delivery for Jones, who somehow blazed wide inside the six-yard box with the goal gaping.
But Boro did find a way through four minutes before the interval. Greenwood’s corner caused problems and the ball ricocheted into the net off the unfortunate Ihiekwe.
Wednesday needed a boost for the second half but it was all Middlesbrough in the early throes.
Emmanuel Latte Lath forced a good save from James Beadle and Boro had two penalty claims waved away.
Lath fired past the post after charging into the box on the angle and Beadle dived to parry a fierce Greenwood strike from danger.
A second goal was coming and duly arrived on 73 minutes. Jones advanced down the right of the area and unleased, and the ball deflected wickedly off Barry Bannan straight into the top corner.
Six minutes later it could and should have been 3-0 when Bannan handled a looping cross and the referee this time pointed to the spot.
Greenwood stepped up but his well-struck penalty came back into play off the upright.
That was a let-off for the Owls but the only thing that ran their way on an afternoon to forget.
Wednesday: Beadle, Valentin (Poveda 61), Ihiekwe, B Diaby (Iorfa 61), Famewo, Johnson, Vaulks (Hendrick 76), Bannan, Musaba, Cadamarteri (Gassama 46), Ugbo (Smith 76)
