Match ends, Leicester City 3, Leeds United 1.
Michael Appleton continued his fine start as Leicester's caretaker boss by guiding them past Leeds United to reach the Carabao Cup last eight.
Pablo Hernandez put Leeds ahead with a stunning 20-yard shot that flew in off the bar, but Leicester levelled through Kelechi Iheanacho's first goal since a £25m move from Manchester City.
Islam Slimani knocked in Iheanacho's cross for a deserved Foxes lead.
Substitute Riyad Mahrez cut inside to fire in as Appleton earned his second win since replacing Craig Shakespeare.
Assistant manager Appleton was placed in temporary charge after Shakespeare was sacked last week, leading the Foxes to only a second Premier League win of the season at Swansea last weekend.
The former Blackburn and Oxford manager said he hoped to "be given a chance" to remain as Leicester's assistant after Saturday's 2-1 victory and did his chances no harm by taking the Foxes into the quarter-finals for only the second time since they won the competition in 2000.
Former Southampton manager Claude Puel is the favourite to replace Shakespeare, according to reports on Tuesday.
However, Appleton says he "expects" to take charge of Sunday's home game against Everton.
"But I know how quickly things can move," he added.
"When I first spoke to the powers that be it was literally just take every game as it comes and make sure the lads are prepared as best as they possibly can be."
Sweeping changes show clubs' priorities
Appleton, like opposite number Thomas Christiansen, shuffled his squad on an EFL Cup night where the 12 teams involved made a combined 80 changes from their weekend games.
The priorities of both managers are clear: Appleton's immediate focus is moving 14th-placed Leicester further away from the Premier League bottom three, while Christiansen wants to take Leeds back into the top-flight for the first time since 2004.
So sweeping changes were not a surprise with Leicester facing fellow strugglers Everton on Sunday, while fourth-placed Leeds host third-placed Sheffield United in the Championship on Friday.
Leicester - showing eight changes from the Swansea win - started slowly against the Yorkshire side, going behind when former Spain international Hernandez was allowed the room to rifle in.
But that jolted the 2015-16 champions quickly into life as Iheanacho calmly slotted in after Leeds goalkeeper Felix Wiedwald scruffily failed to clear a loose ball with his feet.
The home side continued to create the better chances and, after Slimani headed over a gaping goal from inside the six-yard box, the Algerian made no mistake when he reacted quickest to prod in Iheanacho's low cross.
And Mahrez, summoned from the Foxes bench when the score was 1-1, put the game beyond Leeds in the dying moments when he waltzed inside from the right flank to drill into the bottom-left corner.
"It was not ideal going behind, but to come back and play as well as we did was pleasing," added Appleton.
"It was great for Kelechi Iheanacho to produce what he did. It has been stop-start for him, but he's grabbed his opportunity."
Leeds United manager Thomas Christiansen:
"It is never good to lose but the team played a good game.
"We knew about the quality of the Leicester team and I am proud and happy about the performance of the team, especially in the first half.
"We conceded a goal shortly after our goal and maybe if we could have kept the lead until half-time then who knows?
"But we are realistic about who we played against. Ours was a performance of a lot of work and I can't complain."
- 11AlbrightonSubstituted forMahrezat 65'minutes
- 8IheanachoSubstituted forVardyat 81'minutes
- 3Borthwick-JacksonSubstituted forAylingat 45'minutes
- 23PhillipsSubstituted forVieiraat 71'minutes
- 22CibickiSubstituted forSackoat 65'minutes
- Lee Probert
- Shots on Target
Second Half ends, Leicester City 3, Leeds United 1.
Attempt missed. Ronaldo Vieira (Leeds United) right footed shot from the centre of the box misses to the right. Assisted by Pablo Hernández following a corner.
Corner, Leeds United. Conceded by Ben Chilwell.
Goal! Leicester City 3, Leeds United 1. Riyad Mahrez (Leicester City) left footed shot from outside the box to the bottom left corner. Assisted by Vicente Iborra.
Foul by Harry Maguire (Leicester City).
Jay-Roy Grot (Leeds United) wins a free kick in the attacking half.
Delay over. They are ready to continue.
Substitution, Leicester City. Jamie Vardy replaces Kelechi Iheanacho.
Delay in match Kemar Roofe (Leeds United) because of an injury.
Harry Maguire (Leicester City) wins a free kick in the defensive half.
Foul by Jay-Roy Grot (Leeds United).
Corner, Leeds United. Conceded by Daniel Amartey.
Substitution, Leeds United. Ronaldo Vieira replaces Kalvin Phillips.
Goal! Leicester City 2, Leeds United 1. Islam Slimani (Leicester City) right footed shot from very close range to the bottom left corner. Assisted by Kelechi Iheanacho.
Attempt missed. Kelechi Iheanacho (Leicester City) left footed shot from outside the box is high and wide to the left.
Substitution, Leeds United. Hadi Sacko replaces Pawel Cibicki.
Substitution, Leicester City. Riyad Mahrez replaces Marc Albrighton.
Corner, Leeds United. Conceded by Marc Albrighton.
Corner, Leeds United. Conceded by Ben Hamer.