After throwing away five points with stoppage-time goals in the last two matches, the Owls need to bounce back at Preston to stay in touching distance of the top two.
Nicky Weaver made a surprise return in goal after a long-term injury, as did full-back Jon Otsemobor. Captain Rob Jones, striker Gary Madine, and defender Lewis Buxton were also sidelined by injuries. Former Owls striker Neil Mellor was unavailable for Preston due to a knee injury.
The Owls took a fourth-minute lead through defender Danny Batth.
And they dominated the first half before Ben Marshall fired home a second goal.
Victory keeps Wednesday in third place, behind city rivals United, who beat Hartlepool 3-1.
Afterwards, Wednesday revealed they had completed the signing of goalkeeper Stephen Bywater.
The 30-year-old, who has been released by Derby County, joins the Owls until the end of the current campaign.
Bywater signed for Wednesday on an emergency loan deal from the Rams in September and went on to make 12 appearances for the Owls.
During Bywater’s stint at Hillsborough, Wednesday won eight games, drew three, while slipping to just one defeat.
The former West Ham and Cardiff keeper will be eligible for the Owls’ home clash against Tranmere on 2 January, subject to clearance from the FA and Football League.
For reports and reaction read Sports Monday free inside Monday’s Yorkshire Post newspaper.