Rovers were in control for much of the game but let their guard slip after missing a string of good chances with Dwight Yorke and Andy Cole amongst the worst offenders.
Micky Adams axed his entire back four after the traumatic reversal at Wolves. Out went Matt Elliott, John Curtis, Gerry Taggart and Alan Rogers and in came Andy Impey, Howey, Frank Sinclair and Jordan Stewart.
A knee injury sidelined Riccardo Scimeca while a bad cold confined top scorer Paul Dickov to the bench.
Rovers made three changes to the side beaten by Liverpool in the Carling Cup with Steven Reid, Martin Taylor and Tugay making way for Brett Emerton, Andy Todd and Garry Flitcroft.
City's new look defence had a scare in the opening moments when Ian Walker failed to hold on to an Emerton corner followed by a scramble before Sinclair cleared the danger.
At the other end Brad Friedel was equally unsure when he spilled a James Scowcroft header but Leicester failed to capitalise on the loose ball.
In the 22nd minute Rovers squandered a glorious chance to take the lead when Yorke blazed over from eight yards after Cole had headed down a Barry Ferguson cross.
Blackburn were in the ascendancy and had a penalty appeal turned down after 37 minutes when Impey appeared to block a Vratislav Gresko cross with his arm.
Two minutes before the break Yorke put the ball in the net but the striker had strayed offside and in the last significant action of the half Ferguson hit a 30-yard free-kick just over the bar.
Rovers were quickly back in their groove after the restart with Cole hitting the side netting from 16 yards and then a Yorke cross was diverted into the path of Cole whose low shot was brilliantly turned away by Walker.
On 65 minutes Cole was close again, this time firing an angled drive over the bar.
It was to prove a costly miss because on 75 minutes the Foxes grabbed an unlikely lead against the run of play when Markus Babbel fouled Dickov to concede a dangerous free-kick.
Muzzy Izzet floated the ball in for Bent to get in front of Gresko and guide the ball home from six yards.
With eight minutes remaining Leicester gave themselves a two-goal cushion when Izzet's deep corner was headed back by Elliott to Scowcroft who nodded down for Howey to bundle the ball home from close range.