The Tigers were indebted to a 74th minute winner from Jonathan Walters to claim all three points at The Kingston Communications Stadium.
Danny Allsopp (pictured) fired Hull ahead on 56 minutes before York levelled matters through Lee Nogan, only for Walters to pop up with a decisive second.
Doncaster produced a late salvo at Glanford Park to grasp a 2-2 draw against Scunthorpe, who were ahead through Steve Torpey and Andy Butler, and also playing against ten men after Jamie Price's dismissal.
Michael McIndoe's 83rd minute penalty put Rovers back in the game and Leo Fortune-West rescued a point in the dying stages.
Oxford United's promotion hopes suffered a knock as they lost at Leyton Orient, with Gary Alexander's goal settling the affair.
Mansfield Town and Huddersfield Town were other promotion aspirants who endured disappointing defeats as they were beaten by Rochdale and Darlington respectively.
Gary Jones' 12th minute penalty put Dale in front and they were further ahead on 27 minutes through Paul Connor. Leo Bertos completed the scoring in the second half.
Huddersfield crashed to a surprise home defeat to struggling Darlington, who had Ian Clark's spot kick and Neil Maddison's goal to thank for the points.
Yeovil Town took advantage of those slip-ups with a slender win at Kidderminster, which was sealed courtesy of Gavin Williams.
The Lincolnshire derby ended all-square with Marcus Richardson's 40th minute equaliser cancelling out Neil Redfearn's early goal for Boston.
Carlisle continue their valiant fight for survival in good heart after coming from behind to garner a crucial victory at home to Bury.
Gareth Seddon had put the visitors in front but goals from veterans Paul Simpson and Kevin Gray earned Carlisle the success.
Play-off rivals Swansea City and Torquay locked horns at Vetch Field, with the visitors coming out on top due to Jo Osei-Kuffour's late winner.
David Graham had The Gulls in front for a long period before Kevin Nugent's 81st minute leveller. Kuffour pounced with five minutes left on the clock.
Two goals in the space of a minute gave Cheltenham victory at Macclesfield, who had been ahead through John Miles.
Danny Whitaker put through his own net to level matters on 26 minutes and, 60 seconds later, Grant McCann notched the winner.
Northampton Town boosted their play-off ambitions at home to Bristol Rovers, as goals from Magno Vieira and Martin Smith secured the success.
Lawrie Dudfield's 43rd minute goal was enough to give Southend United a much-needed win at home to Cambridge United.
