Having lost their first two games of the Championship campaign and with off-field protests against chairman Ken Bates causing a stir, manager Simon Grayson desperately needed a win against City and his players duly delivered on Tuesday night.
In a near-faultless performance, Ross McCormack, Tom Lees - whose own goal had brought Hull level - Robert Snodgrass and Ramon Nunez all found the net, against a Tigers side who came into the game well-fancied.
Having won at Ipswich on Saturday and with Leeds running with a threadbare squad owing to injury and suspension, a first Hull win in West Yorkshire in 24 years had looked to be an option, but Nigel Pearson's men were rarely in the game.
With Max Gradel and Jonny Howson suspended after their red cards against Middlesbrough at the weekend and Leigh Bromby injured, Grayson was forced to make three changes, the most notable of which was the handing of a second debut to new signing Andy Keogh.
Hull made just the one alteration, with the injured Tom Cairney replaced by Andy Dawson, but it looked as though it were they who had made the most changes as Leeds dominated the opening exchanges.
Scotland winger Snodgrass was at the heart of all their industry, with his cross nearly falling for Darren O'Dea, before he cut inside to work Peter Gulacsi at his near post.
Hull then failed to deal with a Snodgrass cross but Nunez could only send a tame effort wide, before a counter-attack ended with McCormack's shot being deflected wide.
The chances continued to come and it was of no surprise when Leeds went ahead, although McCormack needed three chances to do it.
First of all he headed over after Nunez's 20-yard shot came back off the bar. Then, in the subsequent move, Snodgrass stood up a cross and, although McCormack's first header was beaten away by Gulacsi, he was able to nod the rebound home.
Eager for a second, Keogh cut in and drilled over, and Hull looked to be void of ideas until, in the 20th minute, Robbie Brady's cross fizzed across the Leeds box and Lees, under pressure from Matty Fryatt, rammed it into his own goal.
Hull enjoyed a spell of pressure after that, with their five-man midfield overpowering the four of Leeds but, with two in attack, United were able to get their foothold back and scored again five minutes before the break.
Keogh won a tussle with Jack Hobbs to allow McCormack to get a shot in and, although Hobbs recovered to block it behind, from the resulting corner Nunez's low centre was spilled by Gulacsi, with Lees on the spot to score at the right end.
Hull brought on Aaron McLean at the break in a bid to create more chances but before he could even touch the ball his side were two goals down.
Hobbs felled McCormack inside 15 seconds and Snodgrass, who scored his first goal for his country last week, gave Gulacsi no chance with a replica of the 25-yard free-kick he scored against Hull last season.
Battering ram Dele Adebola was also thrown on by the visitors as they looked to stay in touch, but even when they did get a chance with McLean's back-post header, Andy Lonergan was equal to it.
Hull then withdrew the dangerous Brady, sending on veteran ex-Leeds forward Nick Barmby, but he could only watch on as the home side made it four with 22 minutes left as Nunez's precise finish from McCormack's inch-perfect pass gave him his third of the season.
Lonergan was called into action on a couple of occasions as Hull staged a late rally, but it was too late by then.