A Chris Maguire penalty was enough for the Owls to beat bottom side Blackpool and secure only their third home league win of the season.
Maguire netted from the spot after Stevie May was controversially adjudged to have been fouled by Peter Clarke.
Though victory for the Owls was largely expected against the side propping up the Championship, they were made to work for the three points and their usual jitters in front of goal threatened to haunt them.
May, Royston Drenthe and Lewis McGugan were all guilty of missing glorious chances to give the Owls a more comfortable Boxing Day afternoon at Hillsborough.
And it took a brilliant save from Keiren Westwood, denying Ishmael Miller from point-blank range with a stunning stop, to keep the visitors out.
Blackpool also missed chances through former Owls loanee Chris Eagles and Nathan Delfouneso.
The Seasiders finished the game with ten men after Miller was sent off for his second yellow card in the final minute.
The victory lifted Wednesday to 14th in the table and saw them close out 2014 on home soil on a much happier note than usual.
Wednesday: Westwood; Palmer, Lees, Dielna, Mattock; Maguire, Drenthe, Semedo, McGugan (Lee 79), Helan; Maguire, May (Nuhiu 85). Subs not used: Kirkland, Zayatte, Maghoma, McCabe, Lavery.
Blackpool: Lewis; McMahon, Daniels, Clarke, O’Dea (Dunne 80); Eagles, Perkins, O’Hara, Murphy (Mellis 52); Miller, Davies (Delfouneso 28). Subs not used: Parish, Waddington, O’Keefe, Lundstrum.
Referee: James Adcock (Nottinghamshire)