Hull now face what could be a pivotal week as they play promotion rivals Ipswich Town and Millwall.
At Fratton Park the Tigers thought they had continued their momentum from Tuesday’s win over Derby as McBurnie put the ball in the net after Joe Gelhardt’s effort was saved, only to see the linesman’s flag go up for offside.
The early let-off spurred Pompey into action, with Terry Devlin’s long-range effort drawing an unconvincing save from Tigers’ Ivor Pandur.
The goalkeeper put those nerves to rest soon after, producing a terrific stop from Regan Poole at close range, as the visitors’ were unable to clear a Pompey corner.
Segecic was next to try his luck for the home team, going it alone before firing across goal from a difficult angle.
After the break, the deadlock was eventually broken through a huge lapse in concentration.
Segecic had already been lucky to get away with one short pass before repeating the same error in his own penalty box.
Schmid was able to scramble the ball away from the diving McBurnie, but only as far as Crooks who connected perfectly to send the ball into an empty net.
Despite peppering the Hull goal in the closing stages, Pompey were unable to find a leveller, leaving the home fans and boss John Mousinho to reflect on yet another frustrating defeat.
