Leicester missed the chance to move level on points with sixth-placed Leeds in the final npower Championship play-off spot as Coventry halted a four-match losing run at the Walkers Stadium with a 1-1 draw.
A mistake from Leicester keeper Ricardo saw Marlon King put Coventry ahead but Kyle Naughton equalised on the stroke of half-time with a spectacular strike.
Martin Cranie was sent off after receiving a second yellow card in the 90th minute but Coventry held on.
The last four M69 derby matches have now ended all-square and this one leaves Leicester in seventh spot two points behind Leeds, who lost 3-0 at promotion rivals Swansea in the early kick-off.
Darius Vassell was restored to the Leicester attack in one of two changes made by manager Sven-Goran Eriksson.
The former Aston Villa and Manchester City striker replaced Lloyd Dyer while Yuki Abe was brought back into the midfield. That meant Jeffrey Bruma dropped back into defence in place of Ben Mee, who was on the bench.
Coventry were unchanged from the home defeat to Swansea on Tuesday night.
Leicester dominated the early stages and twice went close through Ayegbeni Yakubu.
First the Nigerian seized on a lose ball following a defensive mix-up and was closed down by Coventry keeper Keiren Westwood. He then scuffed a shot wide from a Kyle Naughton cross.
It was against the run of play when Coventry went ahead after 14 minutes with their first real attack.
Lukas Jutkiewicz advanced down the right and pulled a cross back behind the retreating Leicester defenders. King adjusted well but his shot was straight at Ricardo. However, the ball went through the hands of the Portuguese and into the corner of the net.
King could have scored his and Coventry's second goal when he skipped round Ricardo. But with Sol Bamba and Richie Wellens covering on the line King missed the target.
Ricardo then made an excellent one-handed save at his near post to keep out a Jutkiewicz effort. From the resulting corner, Richard Keogh's header clipped the top of the crossbar.
Leicester felt they should have had a penalty in the 34th minute when Yakubu went to ground after nudging the ball past Westwood but referee Graham Scott ignored the appeals.
It would surely have resulted in a red card for Westwood had the spot-kick been given and the Republic of Ireland international rubbed salt into Leicester wounds by making a superb close-range save to thwart Yakubu a minute later.
It looked like Coventry would hold on until half-time but Naughton equalised in spectacular fashion in the final minute of the half.
The on-loan Tottenham full-back burst into the penalty area and smashed an unstoppable shot into the top left-hand corner with his supposedly weaker left foot.
Naughton continued to pose a threat after the break and another of his surging runs created a chance just after the hour mark.
He was fouled by Cranie and Yakubu's header from the resulting free-kick brought a parrying save from Westwood before Bamba blasted the rebound against the outside of the post from a tight angle.
King failed to make the most of a free header when David Bell found him unmarked in a crowded penalty area midway through the second half.
Chances were at a premium in the second half and when Patrick Van Aanholt blazed a shot over the crossbar from close range with two minutes remaining it was clear the game was destined to end in a draw.
Leicester`s hopes of snatching more than a point received a boost when Cranie fouled Martyn Waghorn and was sent off, but Eriksson's side were unable to muster one final chance.
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