Sunderland moved up to sixth place in the Coca Cola Championship after chalking up a third successive victory.
Graham Alexander gave managerless Preston hope by cancelling out Stephen Elliott's opening goal, but Darren Carter celebrated the start of a three-month loan spell from Birmingham by restoring the lead and when Elliott scored again shortly after the break, the outcome was never in doubt.
A lack-lustre first half burst into action in the 26th minute when Sunderland deservedly surged into the lead. Goalkeeper Andy Lonergan failed to hold on to a low drive from Julio Arca and Elliott swept home the loose ball from close range.
Preston should have been level within a minute but Richard Cresswell fired wide after his first effort had been blocked.
Cresswell, however, was involved in a controversial incident in the 38th minute which led to an equaliser. Referee Alan Kaye ruled Caldwell had wrestled Cresswell to the ground from a free-kick and Alexander made no mistake from the penalty spot.
Arca latched on to a shrewd pass from George McCartney only to shoot past the post but the Black Cats regained the lead on the stroke of half-time with the referee again pointing to the spot when Marcus Stewart went down under an Alexander challenge.
Although Lonergan brilliantly saved from Stewart, Carter was first to react and he blasted the loose ball home from an acute angle.
Hopes of a comeback by the visitors were snuffed out in the 52nd minute following another well-worked move down the left with Arca finding the overlapping George McCartney whose centre was converted by Elliott.
Mart Poom saved well from Eric Skora but cause for more concern for the Black Cats was the loss of Carl Robinson, stretchered off in the 65th minute with a leg injury.