Oli McBurnie had gone 43 games without scoring until he struck at Luton last month, but his third goal in as many matches put the visitors in control after 20 minutes.
Sander Berge then added a second with 15 minutes remaining after he pounced upon loose marking inside the right channel of the penalty area.
Berge's strike might have been fortunate to have taken a sizeable deflection off defender Jacob Greaves, but it was ample reward for a man-of-the-match performance.
The Blades are now unbeaten in the league since the opening day of the season and were, despite a few scares along the way, good value for three points against disjointed hosts.
Hull made numerous eye-catching signings during the transfer window, with optimism high amongst supporters that they now have a squad capable of challenging for the play-offs.
But, ultimately, they paid the price for a sluggish start in front of a big crowd at the MKM Stadium - and never launched a sustained challenge to threaten their well-drilled Yorkshire rivals.
Indeed, Hull ought to have been 1-0 down after 18 minutes when Oliver Norwood's reaching cross towards the right was expertly volleyed across the face of goal by George Baldock.
McBurnie was, though, caught flat-footed and failed to react to what should have been a routine half-volley from close range.
The Scotland international made amends two minutes later - though Hull goalkeeper Matt Ingram was desperately at fault for Sheffield United's opener.
McBurnie was allowed by Alfie Jones to squirm into a shooting position towards the left-hand corner of the 18-yard box. His strike was on target, but Ingram somehow allowed the football to scuff beneath his body at his near-post.
Just when United looked set to cut loose following that deserved opener, Hull created their best chances of the game after 27 minutes.
Callum Elder did well to break down an eager counter-attack, from which his clearance found Oscar Estupinan out on his own inside the centre circle. Estupinan drove inside the Blades' penalty area but looked jaded by the time he shot at Wes Foderingham, who reacted well to the initial effort before doing even better on the follow-up from the Portuguese.
Any momentum Hull had hoped to build after the restart was quickly subdued by a combination of wayward passing and neat possession-based football from Paul Heckingbottom's side.
Shota Arveladze's men at least rallied gamely as the second half progressed - most notably once influential playmaker Jean Michael Seri returned from injury as a substitute.
But once Berge quietened the raucous home support with a second after 75 minutes, a routine away win was never in doubt.
Narrow win for Blackpool
Canada international Theo Corbeanu's third goal in four games earned Blackpool a narrow 1-0 Championship win at struggling Huddersfield.
The on-loan Wolves striker's first-half effort consigned the hosts to a sixth defeat in eight games in all competitions, with Danny Schofield's men having also failed to keep a clean sheet in any of those contests.
But a controversial incident appeared to deny the hosts a share of the spoils when a second-half Yuta Nakayama effort was judged not to have crossed the goal-line.
Earlier, during an even opening, a long-range Corbeanu effort sailed over the home crossbar, while Sorba Thomas' 15-yard drive was smothered at his near post by Seasiders goalkeeper Daniel Grimshaw.
On-loan Aston Villa wing-back Kaine Kesler-Hayden then saw his deflected shot miss the target for the Terriers, before Jordan Gabriel could not apply a finishing touch to Jerry Yates' ball across the six-yard box and a Corbeanu drive was routinely gathered by Lee Nicholls.
As the half wore on, Huddersfield began to apply greater pressure, winning a series of corners, one of which saw Jack Rudoni head wide from a Thomas delivery.
Danny Ward also fired wide after turning on the edge of the box and Rudoni called Grimshaw into a flying save from 30 yards after Marvin Ekpiteta's poor ball out of defence.
But it was the visitors who forged in front after 38 minutes when Kesler-Hayden was dispossessed on the halfway line by Gabriel.
The latter then sprinted down the right wing before squaring to Ian Poveda, who hit Nicholls' right-hand post with only the home keeper to beat before Corbeanu kept his composure to neatly finish from the rebound from 10 yards out.
Rudoni continued to look the biggest threat for Huddersfield and stung Grimshaw's hands from just inside the penalty box on the stroke of half-time.
After the break, Ward's header from a Thomas cross lacked the power to extend Grimshaw, while a deflected Poveda drive drifted wide.
The game's biggest talking point then saw Nakayama denied what looked a certain goal just past the hour, as the Japan international appeared to prod the ball over the line after his initial header from Thomas' corner had been brilliantly repelled by Grimshaw.
But Grimshaw grabbed the ball and played on and, with the goal-line technology appearing to have malfunctioned, Nakayama had to quickly curtail his celebrations as the action switched upfield.
Moments later, Poveda's on-target strike was diverted away from goal by Ollie Turton, before Huddersfield went back on the attack with Jon Russell curling an effort wide from 20 yards after Corbeanu had given the ball away.
But the Terriers failed to stage a grandstand finish in front of a frustrated home crowd with substitute Jordan Rhodes heading his team's final opportunity well off target.