Blackburn stunned Leicester to reach the FA Cup quarter-finals.
Tyrhys Dolan and Sammie Szmodics cashed in on awful defending to clinch a 2-1 win and send Rovers into the last eight for the first time since 2015.
Jon Dahl Tomasson’s side upset the 2021 winners, despite Kelechi Iheanacho pulling a goal back.
Brendan Rodgers celebrated four years in charge at the King Power Stadium on Sunday and this defeat marked his 200th game.
No-one can dispute the progress in his first two years, which culminated in the first FA Cup triumph in the club’s history, but this season in particular has been a slog.
Two wins in their last nine Premier League games has long since halted their momentum away from the relegation zone but reaching an FA Cup quarter-final would have given a natural boost ahead of the final scramble over the line.
Instead, defeat by Blackburn, inconsistent in an average Championship, is another nail in the coffin of a season the Foxes would rather forget.
Not that Rovers were undeserving winners. They seized on every mistake – and there were many – to punish the hosts and maintained their composure as Leicester launched a late assault, with Daniel Amartey hitting the post.
Six changes, including a first start for Ricardo Pereira since May 2022 after his recovery from a ruptured Achilles, still did not initially dilute the Foxes’ early quality and they should have gone ahead after eight minutes.
Dennis Praet was too unselfish when presented with space on the edge of the area and fed Tete who was denied by Aynsley Pears. The rebound, though, fell kindly for Praet who should have done better than fire straight at Pears.
The Rovers goalkeeper then stood up to Jamie Vardy’s angled effort but, not to be outdone, the visitors created some dangerous openings.
They had been encouraged by Leicester’s wastefulness and the Foxes’ failings at the back only motivated them further.
First, Luke Thomas’ slip allowed Dolan a chance before Daniel Iversen had to be alert to keep out Szmodics after the Foxes lost the ball, although the forward’s finish was poor.
Blackburn had grown into the game as the Foxes’ threat waned and the haphazard nature of the hosts’ defending was a serious cause for concern.
Even a routine long ball caused problems as a missed header from Wout Faes and a miscued one from Amartey allowed Szmodics to tee up an unmarked Dolan.
The striker was just eight yards out with Iversen to beat but the goalkeeper smothered his low strike.
Yet it was only a brief reprieve when another error was finally punished by Dolan after 33 minutes.
Amartey’s attempt to play out was reckless and ill-advised as his pass was cut out by the forward, who arrowed towards goal and beat Iversen from the edge of the box.
If Leicester had been careless before the break their defending became calamitous immediately after and they fell further behind seven minutes into the second half.
Only Ryan Hedges’ wasteful finish had stopped Rovers doubling their lead when Boubakary Soumare was robbed on the edge of his own box but, like before, Leicester failed to heed the warning.
Minutes later, Sam Gallagher’s strong tackle on Thomas saw the striker gallop from the halfway line to find Szmodics on the edge of the box.
There was still plenty for him to do but he bullied his way past Amartey and Pereira and his soft shot rolled gently into the corner.
Another Iversen save kept Szmodics from making it 3-0 soon after with Leicester crumbling.
Rovers were more confident, more determined, but out of the blue the Foxes pulled a goal back with 23 minutes left.
Harvey Barnes found space for the first time and pulled back for Iheanacho to net his now customary FA Cup goal from close range.
Pears also denied the striker with time ticking away and Amartey’s header hit the post in stoppage time.