United's U23s extend their unbeaten record against top-flight opposition on Saturday evening.
But despite Jordan Hallam's early penalty, the Blades were forced to settle for a point at the KCOM Stadium, despite Hull playing much of the game with ten-men.
In a clash, the followed the Tigers Premier League fixture against AFC Bournemouth on Humberside, it was United who struck first, as HALLAM scored from the sport having been hauled down by the last man, who was subsequently given his marching orders.
United's numerical advantage led to the visitors enjoying plenty of possession, but the Blades were guilty of missing a host of chances, with Bennett, Crofts, Hirst and goalscorer Hallam all wasteful in front of goal.
At the other end, the impressive Long made two smart first-half saves to ensure the Blades led at the break, but four minutes into the second period, the home side levelled as TER-HORST showed a burst of pace that saw him beat the challenges of Kelly and Mallon before slotting home.
Despite the concession of an equaliser, the Blades continued to enjoy the best of the game, but with City dropping deep, it became increasing frustrating for the away side who were finding it difficult to lift the tempo.
Hallam's delivery was a threat from set-pieces, with Graham and then Hirst inches away from connecting with balls that flashed across goal, whilst Bennett and Crofts linked up well down the right and created a host of crossing opportunities.
But City's defence defended resolutely to ensure a share of the spoils, as United made it seven games unbeaten in the process.
Academy Manager Travis Binnion remarked: "We weren't at our best, which is disappointing given our numerical advantage for much of the game.
"We should have run out comfortable winners, but in the end we had to settle for a point, as we lacked that touch of quality in the final third.
"Focuses now switch to improving certain aspects of our game ahead of the cup clash with Stoke City."
Blades: Long, Bennett, Mallon (T. Smith 59), Graham, Semple, Kelly, Slater (Gordon 71), Gilmour, Crofts, Hallam, Hirst.
Unused: Eastwood, Cummings, Parkhouse.