Sheffield Wednesday's on-loan duo Danny Batth and Ben Marshall scored a goal each to boost the Owl's promotion hopes at the expense of Preston.
Batth notched first when he headed in Chris Lines' cross following a short corner and Marshall doubled the lead when he fired in from an acute angle.
Ryan Lowe almost grabbed a third but Thorsten Stuckmann saved well.
Preston came close late on but Jamie Douglas saw his effort cleared off the line and Paul Parry headed wide.
VIEWS FROM THE DRESSING ROOM
Sheffield Wednesday manager Gary Megson told BBC Radio Sheffield:
"It was terrific and I thought there were a lot of really, really good performances.
"It was much more professional and much more savvy in terms of when a team is defending corners.
"I had a bit of a disappointment at half-time as we had 10 corners in the first half and had only scored one goal, but I felt we looked solid and threatening.
"In the last few minutes I'll never know how we didn't get a penalty. I'm not sure I've ever seen anything as nailed on as that in my life."