Paul Dickov's late penalty sent Blackburn into the semi-finals of the FA Cup at the expense of Leicester.
Dickov struck in the 83rd minute after Leicester's Darren Kenton brought down Norwegian Morten Gamst Pedersen.
Rovers had enjoyed the best of the few chances that were on offer at Ewood Park, with Pedersen hitting the post from a free-kick early on.
Pedersen's second-half free-kick also flashed across the goal, while Joey Gudjonsson went close for Leicester.
Dickov, 33, cost Rovers £150,000 when he moved from Leicester in the summer, after scoring 37 goals in 97 appearances over two-and-a-half years.
But his late strike handed Blackburn their first FA Cup semi-final since 1960.
Mark Hughes' side dominated the early proceedings and were unlucky not to take the lead in the fifth minute.
Pedersen curled his left-footed free-kick around the wall from 30 yards, beating Leicester keeper Ian Walker, but his shot rebounded off the left upright.
Several minutes later, Blackburn surged forward again and Dickov latched on to a perfectly-weighted through-ball but hit a tame shot straight into Walker's hands.
Leicester's first meaningful attack came after half-an-hour when they won a corner on the right but Keith Gillespie's delivery was easily cleared.
The Foxes took their time to edge into the game and were limited to long-range efforts from Gareth Williams and Gudjonsson.
Just before the interval, Dickov snatched at a half-chance in the Leicester box but his off-balance shot looped wide.
The energy levels shot up immediately after the break as Leicester took the game to their opponents.
But the best opening fell to Rovers' David Thompson, who fired a speculative effort just over the bar from the edge of the penalty area.
As the half wore on, Rovers squandered several more chances as their keeper Brad Friedel watched on with little to do.
On 67 minutes, Pedersen's free-kick from near the right byeline squeezed through a jumble of bodies jostling in the goalmouth.
Shortly after, Australian defender Lucas Neill fell inches short of getting his outstretched boot on to a cross, with the Leicester goal gaping.
But the game turned inside the last 10 minutes when Kenton clattered into Pedersen and referee Neil Barry pointed to the spot.
Dickov blasted his penalty straight down the middle and Blackburn held firm to progress to the last four.
Blackburn: Friedel, Neill, Todd, Nelsen, Johansson, Mokoena (Stead 56), Thompson, Flitcroft, Reid (Emerton 67), Pedersen, Dickov.
Subs Not Used: Enckelman, Tugay, Matteo.
Goals: Dickov 83 pen.
Leicester: Walker, Kenton, Dabizas, Dublin, Maybury, Gillespie, Williams (Hughes 87), Gudjonsson, Nalis (McCarthy 86), Tiatto (Connolly 87), de Vries.
Subs Not Used: Hirschfeld, Stewart.
Booked: Dabizas, de Vries, Tiatto, Gillespie.
Ref: N Barry (N Lincolnshire).