Whittaker’s return to the side was keenly felt and he warmed the palms of Cooper shortly after breaking the deadlock. Matt Targett and Tommy Conway then combined down the left to create a chance for David Strelec as Boro searched for a decisive second goal.
Wednesday were unbeaten in their previous three outings, having held Leicester City, champions Coventry City and Charlton Athletic, but they offered little threat in the first half and a wayward drive from Jarvis Thornton was as close as they came to drawing level before the break.
Boro continued to dominate the ball and probe at the beginning of the second half, but Whittaker and then Aidan Morris – after good individual work to regain possession in midfield – lacked conviction as they both tried their luck from distance.
While the scoreline remained 1-0, the Owls were never out of the contest and substitute Jamal Lowe prompted panic with his low shot from inside the penalty area, following a rare foray forwards, deflected wide of the near post.
The visitors’ vociferous calls for a penalty kick were waved away by referee David Webb when Max Lowe appealed for handball against Morris, who was subsequently awarded a free-kick himself after he went to ground inside his own box.
Wednesday, throwing more caution to the wind, then forced Boro goalkeeper Sol Brynn into a smart low save when 17-year-old Will Grainger curled a first-time effort towards the bottom corner.
The game became entertainingly open in the closing stages as Wednesday risked plenty and Boro looked to pick their lowly opponents off on the counter-attack. They came close when Jeremy Sarmiento dinked the ball over Cooper, but his effort was helped clear by the recovering Tayo Adaramola.
One goal was ultimately enough to end Boro’s winless streak and, although unconvincing, it keeps their automatic promotion hopes alive.