Ipswich ended the pressure on manager Roy Keane as his side ended their losing streak in a bizarre npower Championship clash played in atrocious conditions at Portman Road.
Keane's side had lost their previous six games but roared into a 3-0 lead in the first half against Sven-Goran Eriksson's men in heavy snow thanks to goals from David Norris and a Jason Scotland brace.
The match was held up by a 15-minute interruption in the second period as referee Stuart Atwell took the players off to allow groundstaff to clear snow from the playing surface.
Keane must have feared the worst but Atwell allowed the players back on to complete the job and pick up three vital points.
Atwell had passed the pitch playable at a lunchtime pitch inspection but the snow continued to fall all afternoon and even though the groundstaff had painted all the lines blue, they were barely visible by kick-off.
Leicester captain Andy King almost got on the end of a through ball before debutant Chris Kirkland was picking the ball out of his net in the sixth minute.
Jack Colback sent a long free-kick forwards for Damien Delaney to head back across goal.
Shane O'Connor helped it on to Rory Fallon who - with his back to goal - did well to lay the ball off to Norris on the edge of the area.
The captain got over the ball well and drilled his left-foot shot through a crowd of players and into the far corner to give Ipswich a dream start.
Fallon tested former England goalkeeper Kirkland with a powerful header from the edge of the area as the home side settled well in the difficult conditions.
Eriksson's men were within inches of a leveller in the 15th minute.
Paul Gallagher's free-kick from the left was flicked on by Darius Vassell and Ipswich left-back Mark Kennedy somehow headed the ball onto the inside of the post from just three yards out.
The home side were dominating though and deservedly doubled their lead in the 27th minute.
Fallon was crucial in the build-up again, holding up the ball well and turning to pick out Scotland on his left and the Trinidad & Tobago international drilled a crisp drive across Kirkland and into the net.
Eriksson made a quick change, bringing on target man Steve Howard in the hope that he could replicate Fallon's impact at the other end, but it was Keane's men who instead increased their lead in the 39th minute.
O'Connor made the run on the left of the area and though Yuki Abe seemed to win the ball, he hesitated to allow O'Connor the chance to pick out Scotland on the six-yard line for a tap-in.
The work for the groundstaff continued at the break as they cleared snow from the pitch but it continued to fall heavily as the second period began.
Gallagher had the first sight of goal with a tame effort at Marton Fulop before O'Connor curled over the top.
Eriksson, Keane and Atwell then gathered for a conversation just before the hour mark and the players soon left the field to allow the staff to work on the pitch again for a 10-minute period.
Atwell called for an extra five minutes and then decided to resume from the 59th minute and Curtis Davies thought he had instantly pulled one back only to see his volley chalked off for offside.
And Leicester's miserable afternoon was concluded when Angelo Miguel Vitor pulled his hamstring with 15 minutes left, forcing the Foxes to finish with 10 men.