Kiko Cassilla's eight-match suspension for alleged racist language meant teenager Illan Meslier was making his Championship debut for the Whites but it was his opposite number, George Long, who had to show his brilliance to keep the scoreline down to 4-0.
Leeds flew out of the traps, scoring after just six minutes and hitting the crossbar shortly afterwards but the Whites have been playing in binary recently and they were unable to go for Hull's throat in the first half.
Once Pablo Hernandez doubled the lead after 47 minutes, they showed their teeth and swept Hull away.
The roof only really started coming in during the final 10 minutes, when Tyler Roberts helped himself to two goals.
Luke Ayling's deflected shot had put Leeds in front and when Hernandez rattled the bar shortly afterwards, you feared for the visitors, in freefall since New Year's Day. They steadied the ship, but it was only a temporary reprieve.
The Tigers had changed from their usual shape to go with a midfield diamond, Mallik Wilks partnering Josh Magennis up front, while Leeds put Stuart Dallas in the middle to beef it up, leaving them with the lop-sided three-man defence they employ from time to time – effectively a back four with the left-back missing.
After the initial flurry, the game slipped into a slumber. Hull showed signs they were getting to grips with it but were unable to seriously test Meslier.
The only shot the Tigers had in the opening period came after 24 minutes., Leandro Da Silva Lopes working well on the right to start the move, but when Kevin Stewart hit his shot, the deflection worked in the goalkeeper's favour this time and he held on comfortably.
Unfortunately, there was more action in the stands, with Leeds fans led from the West Stand into the busy away section, and escorted out of the East Stand after an early flashpoint.
Leeds were brilliant on the counter-attack in the second half, and Hernandez's goal came after Josh Magennis found space at a corner but, pulling back, was only able to head at Meslier.
The visitors broke and Jack Harrison's cross found Helder Costa, who laid the ball back for Hernandez to fire in.
Harrison was brilliant in the second half, but so was Long. He made a good low save from Costa, whose footwork had given himself an opportunity, tipped an excellent Harrison shot around the post, and made a flying save from Costa's volley after the Portuguese was picked out by Harrison.
Patrick Bamford stabbed wide at a free-kick.
With Harrison hitting a shot against the post, it looked like Hull might get off lightly. Substitute Norbert Balogh even rattled Meslier's upright with a fantastic turn and shot, but it was out of keeping with the flow of the game.
Roberts came off the bench to replace centre-forward Bamford after 67 minutes, and gave the scoreline a fairer look.
The first rounded off a brilliant counter-attack. Harrison, Costa and Mateusz Klich all had a lot of space as they swept their team down the field, and Dallas almost got in Roberts' way as he put his side 3-0.
He then headed in a fourth from Klich's cross.
If anything, Leeds deserved more against a Hull team caught in the headlights.
After their mid-season wobble, Leeds look well placed against for automatic promotion. If the Tigers are not careful, they could end up leaving the Championship too.
Hull City: Long; McKenzie, Pennington, McLoughlin, Elder; Stewart; Da Silva Lopes (Batty 63); Honeyma; Samuelsen (Maddison 76); Magennis (Balogh 63), Wilks.
Unused substitutes: Tafazolli, Ingram, Kingsley, Irvine.
Leeds United: Meslier; Ayling, White, Cooper, Dallas; Phillips; Helder Costa, Hernandez (Shackleton 87), Klich, Harrison (Alioski 87); Bamford (Roberts 67).
Unused substitutes: Douglas, Caprile, Berardi, Stevens.
Referee: Keith Stroud (Hampshire).