Derby 1-0 Leicester
Chris Weale's woeful error cost Leicester dearly as Derby County took home all three points in a tightly contested affair at Pride Park.
Weale failed to control a passback from Andy King midway through the first half to gift the Rams victory in what was ultimately an even contest.
It was a bitter blow to Leicester's play-off hopes, with both Cardiff and Blackpool both claiming victories on the day.
Manager Nigel Pearson made three changes to his starting lineup from the side which lost to Reading midweek, with Wayne Brown, Chris Powell and Yann Kermorgant coming in for Nobby Solano, Ryan McGivern and Paul Gallagher.
In a dreary first half it was the Foxes who took hold of most of the possession, without testing Derby goalkeeper Stephen Bywater significantly.
City started the brighter of the two sides and were creating most of the play in the opening 15 minutes without avail.
But in the 19th minute disaster struck in embarassing fashion. Andy King did well inside the penalty area to break up a Rams attack, but his routine pass back to goalkeeper Chris Weale was shamefully mis-controlled, the ball rolling into an empty net for the opener.
Whilst Derby fans let out roars of laughter, their Leicester equivalents were left to ponder what had just occured.
Martyn Waghorn could have equalised almost immediately afterwards when he latched onto Richie Wellens' ball over the top, but he was signalled offside.
Neither goalkeeper was being tested in the first period in a cagey tussle between both sides. Jack Hobbs was once again proving solid at the heart of defence for City to regularly break up Derby attacks.
Leicester came close to an equaliser close to half-time when Wellens' brilliant 25-yard effort was matched by a fine stop from Bywater.
The second half began in much the same vein as the first, with neither side able to force any kind of opening. Frenchman Yann Kermorgant was winning most of what came his way in the air, but the ball simply would not drop to a blue shirt.
It was soon becoming clear that Leicester's system was not working, so it was no surprise when Pearson brought on former-Ram Steve Howard and Paul Gallagher for Kermorgant and Waghorn, foreshadowing a remaining half an hour of long ball football. In truth it wasn't always like that, with most of City's better opportunities arriving when allowed to pass the ball.
Richie Wellens attempted a speculative effort close to the halfway line when Bywater had been found stranded, but the ball bounced safely wide with the goalkeeper managing to recover comfortably.
The Foxes applied pressure on the Derby backline from a corner, but the Rams backline held firm to avert danger as far as Richie Wellens. The midfielder again found himself with another opportunity for City, but his effort on the edge of the area sailed horribly high and wide of Bywater's goal.
Dany N'Guessan was finally brought on for Matt Oakley with 15 minutes remaining, and in truth did more than most of City's forward line put together. Buzzing around the wings, his introduction caused problems early on for the Rams defence.
There were calls for a late penalty with ten minutes remaining when Paul Gallagher was brought down inside the area, but play was waved on with the Scot barely appealing himself.
The glorious opportunity came minutes later when Steve Howard's header down from a corner was flicked straight at Bywater by Michael Morrison. Anywhere either side and City would have been level.
The opportunity simply epitomised Leicester's day. The full-time whistle blew, ending another match of dropped points for Pearson's men.
It was a game lost by a horrible moment of madness from a usually reliable goalkeeper, simply adding to City's woes of late goals in their last two matches.
With difficult and important matches away at Cardiff and West Brom this week, Leicester fans will be praying the wheels of the promotion wagon have not fallen off prematurely. But, as usual, it looks like we're going to do this the hard way...