Chemsdine Talbi scored on his Sunderland return as the Black Cats got the better of Hull and sealed their spot in the fourth round of the Carabao Cup.
Talbi, who was not included in his club's Europa League squad last week and has been the subject of interest from Saudi Arabia, scored the only goal in a game which lacked many clear-cut chances.
The first half provided little excitement apart from when Hull were denied an early penalty shout when Luke O'Nien appeared to foul Robinio Vaz in the box.
Sunderland opted to make 11 changes from the side who drew at Brentford on Saturday and the rustiness of second-choice keeper Melker Ellborg was clear when he surged out in an attempt to claim the ball outside of his box and mistimed his move, but Hull's Mohamed-Ali Cho was unable to direct his lob on target.
The hosts subjected Hull to a late flurry of first-half attempts and nearly broke the deadlock when Jules Ahoka whipped an effort towards the far corner, but Dillon Phillips did well to dive down and keep it out.
They finally broke the deadlock through Talbi in the second half as the Morocco international raced up the pitch in a counter-attack and dinked the ball over Dillon Phillips.