Sam Allardyce's Blackburn hauled themselves eight points clear of the relegation zone and left Hull deep in trouble with a hard-fought 1-0 win at Ewood Park.
Blackburn got the game's only goal in the 16th minute when Martin Olsson's effort was deflected in by goalkeeper Boaz Myhill.
The visitors then had George Boateng sent off towards the end of the first half and they were unable to get back in the game. Hull are now just a point outside the bottom three.
Blackburn thoroughly warranted their victory and enjoyed lots of early possesion, with Ryan Nelsen and El-Hadji Diouf both going close.
Blackburn opened the scoring after Morten Gamst Pedersen set Olsson scampering away down the left. The full-back's shot from the by-line got a final touch off Myhill, for an own goal.
Hull's troubles increased when they were reduced to 10 men. Boateng was red-carded after needing treatment following a challenge on Pedersen in the middle of the park, while Blackburn were unlucky not to end up with another goal as they created a number of second-half chances.