There was an early opportunity for Maguire, who bent a free kick just over for the bar.
Ishmael Miller did well down the left but Chris Eagles couldn't connect with the striker's cut-back before good play from Wednesday saw Maguire play the ball over the top for Stevie May, who clipped over the goal.
Blackpool's response came in the form of Jacob Murphy as he sent an 18-yard effort just past the post.
Following the restart, Maguire raced into the area and his deflected cross crashed against the bar before May headed over the top.
Miller put the ball in the net for Blackpool but he did so using his hand and was booked after the goal was disallowed.
Lewis then produced a fine save from May's header as he got a strong hand to the ball to deny the Scottish striker.
At the other end, Kieren Westwood was forced into a great save of his own after he kept out Miller's header from four yards.
Blackpool's poor day was then compounded as Miller was shown a second yellow card late on after a foul on Tom Lees.