Blackpool led in the sixth minute when Claus Jorgensen outfoxed several Wednesday defenders to engineer the space for a shot which beat Lee Grant.
Wednesday drew level on 12 minutes through Richard Wood.
Jermaine Johnson was fouled by Stephen Crainey and Franck Songo’o’s free-kick from the right was headed home by the defender.
Blackpool’s Paul Dickov then struck in clinical fashion on 30 minutes.
Kaspars Gorkss flicked the ball into the box and the striker netted with a brilliant left-foot volley.
Wednesday went close to an equaliser in the 50th minute when Bartosz Slusarski sidefooted the ball wide.
Moments later Wednesday’s Peter Gilbert was shown a straight red card for appearing to butt Dickov.