The Foxes went into the clash as clear underdogs despite taking the scalp of Aston Villa in a 1-0 victory in the previous round of the competition.
Leicester started well and took the lead thanks to Gareth McCauley's well taken header after just six minutes.
However, two Frank Lampard goals gave the home side the advantage at the break.
The Blue Army had more to cheer about when substitute DJ Campbell guided a nimble header over the head of Carlo Cudicini to level the score. The Home fans were again stunned into silence minutes later when Carl Cort gave City the lead. At 3-2, the Foxes were in heaven.
Unfortunately, The Foxes were unable to hold onto the lead and two late Andriy Shevchenko goals prevented the biggest shock of the season to date.
Although Leicester are out of the Carling Cup, the work ethic of the team last night was immense and the travelling Blue Army were left with nothing but pride and passion for their team.
And don't forget, we may still be planning a trip to Wembley through the Play-Offs or the FA Cup final perhaps!?