Mallik Wilks' late penalty secured Hull's promotion to the Sky Bet Championship and edged closer to the League One title in a 2-1 win at Lincoln.
Josh Magennis put Hull into an early lead, only for the visitors to be pegged back by Lewis Montsma's effort.
But just when Hull feared a frustrating draw, up popped Wilks with the winner from the penalty spot to seal their place in the second tier.
Peterborough's 1-0 win at Charlton, however, meant that Hull were not able to pop the champagne on a title victory.