Hull missed the chance to close the gap on npower Championship leaders Cardiff as they were convincingly beaten by Bolton.
The promotion-chasing Tigers, who have not conceded in their last two matches, saw their defence breached three times in a remarkable opening eight minutes at the Reebok Stadium.
Darren Pratley headed in the opener after an excellent cross from Lee Chung-yong before influential midfielder Mark Davies added a second.
Things got worse for the Tigers when on-loan West Brom defender Craig Dawson made it 3-0 from a corner, leaving the Tigers with a mountain to climb.
Ex-Manchester United winger Robbie Brady gave his side - five points behind the Bluebirds who play Wolves tomorrow - a lifeline in the 65th minute, but their hopes were soon ended when Dawson netted his second.
Bolton, on the other hand, move further away from the relegation zone with a victory that extends their unbeaten run to four matches.
The Trotters broke the deadlock in the second minute when Davies played in Lee and his cut-back was powerfully headed home by Pratley.
Davies then got on the scoresheet himself as he found space on the edge of the area and unleashed a shot that on-loan Fulham goalkeeper David Stockdale got a hand to but could not keep out.
Hull looked shellshocked and in the seventh minute Bolton inflicted more misery on the visitors, with Dawson’s glancing header adjudged to have gone over the line before Marvin Sordell made sure.
The Tigers regrouped and Brady had their first chance, firing in a free-kick from a tight angle that Adam Bogdan saved well.
However, Bolton continued to attack and almost added a fourth, but Sordell’s effort from the edge of the box came back off the post after he was played in by David Ngog.
Hull resorted to shooting from distance, with Corry Evans’ effort on the stroke of half-time flying over the top from 35 yards.
The visitors tried their best to get back in the match and after former Sunderland midfielder David Meyler was fouled on the edge of the box, Brady fired the free-kick over the bar.
Brady improved his delivery minutes later, producing a pinpoint cross that Alex Bruce headed over.
The introduction of new loan signing George Boyd and Jay Simpson on the hour mark gave Hull a boost as they pulled a goal back five minutes later through Brady.
The Republic of Ireland international’s 25-yard free-kick went straight through the wall and into the bottom corner.
However, their hopes of a comeback were dashed when the home side regained their three-goal advantage thanks to Dawson’s flick into the bottom corner.
Bogdan denied Brady a second late on, pushing away his header.
Shell-shocked Steve Bruce described Hull’s sloppy opening as “one of those freak things.”
“I’ve had better days,” grimaced Bruce as Hull slipped out of the automatic promotion places.
“That start is something you see at school. How can you explain it?
“It’s one of those freak things. I have never been involved in something like that and I don’t think it will happen again for a long time.
“You have to erase it and say ‘it happens’. Sometimes a kick up the backside doesn’t do anyone any harm now and again.
“We have been rock solid for seven months. The one thing we needed after that was a response and I think you saw there was one.
“But you know it’s not your day when you score to make it 3-1 with 20-odd minutes to go and they go down the other end and score again.
“Bolton have got some good players yet when I looked this morning they were four points above the relegation area. That shows you how difficult this league is.”