Sunderland lost to Blackpool at home, despite having a great record at home. Asamoah Gyan, Darren Bent and Danny Welbeck all squandered good openings and visiting goalkeeper Richard Kingson made a number of excellent stops.
But Campbell shot home from Ian Evatt's headed flick to make it 1-0.
Bent hit the bar with a fine free-kick but Campbell added a second in injury time from Matt Phillips's low cross.
But Sunderland will be left scratching their heads at the result after creating enough chances to have won two games in a refreshingly open and frantic first period.