Hull's hot streak fizzled out with a 3-2 defeat at home to Bristol City, in a match twice halted due to a squirrel on the pitch.
Sergey Jakirovic's men had won four of their last five games to cement a position in the Sky Bet Championship play-off places.
And they looked set to maintain that run of form when Oli McBurnie scored after 24 minutes.
But Bristol City responded with purpose and were 2-1 up at the interval after Rob Atkinson headed home a 33rd-minute corner and Ross McCrorie scored shortly afterwards.
Gerhard Struber's side then put clear water between themselves and Hull when Emil Riis converted Scott Twine's fine assist after 50 minutes.
Not even the presence of a rogue squirrel on the pitch and a second Hull goal from Kieran Dowell in the 78th minute could prevent Bristol City from claiming three deserved points.
Having been thumped 5-0 at home by Derby last week, the visitors might have been forgiven had they adopted a conservative approach at the MKM Stadium.
But any notion of a team lacking confidence proved misguided as Struber's men were the better side in the first half.
They should also have taken an eighth-minute lead when John Egan lost his footing 25 yards from goal.
Riis seized advantage but his shot when through one-on-one lacked conviction and was easily saved by Ivor Pandur.
The Robins continued to create a favourable impression, but that was until McBurnie opened the scoring after playing a neat one-two with Regan Slater.
The in-form striker still had work to do as Radek Vitek raced off his goal-line, but his first touch deceived the goalkeeper who thought he was going to shoot first time.
Home supporters demanded their side kicked on, but Bristol City refused to yield and equalised when Tomi Horvat's inswinging corner from the right caused panic within Hull's back-line.
Atkinson then evaded Lewie Coyle before heading home from the edge of the six-yard box.
Suitably inspired, Bristol City took the lead after 39 minutes.
Pandur initially did well to thwart Horvat but was let down by team-mate John Lundstram who carelessly gave the ball back to the visitors.
Lundstram hardly covered himself in glory in the second phase, either, as Hull could not clear their lines. McCrorie picked up the pieces by ramming the ball into the top-right corner.
Hull brought on Liam Millar and Lewis Koumas at half-time but the double change failed to halt the flow of a game that swung sharply in Bristol City's favour once they scored a third goal.
Former Hull midfielder Twine's brilliant through-ball was taken on the run by Riis, who stayed calm to direct the ball away from Pandur.
Once play finally resumed, the squirrel having been caught and escorted from the premises, Dowell's close-range volley gave Hull hope, but it was not enough.
Hull's Sergej Jakirovic:
"No matter how this season goes, we should all be very proud with what we have achieved - very proud.
"If you had told me we would have had 54 points at this stage of the season, I would have signed for that straight away. I know expectation is very high and maybe this is the problem.
"I'm always optimistic and positive and it is me who has to remove the pressure, but we must enjoy this moment "Congratulations to Bristol, but maybe we need a reset."
Bristol City's Gerhard Struber:
"I'm really happy with the win here but also with how we did it. We worked so hard, and it was teamwork on a really high level.
"After the defeat against Derby, this was a great time to show a reaction with a good performance - and also the chance for momentum.
"I think we had a good energy and preparation. It was not a surprise to see us bounce back. Hull have high-quality players and are really in good form.
"But we found a different behaviour how to play - we pressed higher and were really good in transition. We were clear and sharp in what we did, and we were ready for the points."
