Man Utd drawn to face Tottenham in semis, Chelsea v Southampton
Morata with opener for Chelsea, Vardy equalises for Leicester
Sub Pedro heads winner in first half of extra-time
Hojbjerg & Cedric score as Southampton beat Wigan
Leicester 0-1 Chelsea
Phil Brown
Swindon Town manager on BBC Radio 5 live
Bakayoko wasn't grabbing the game like you expect him to. Last time I watched him was against Watford and he had a horrendous game.
He seems to have lost some form. It is certainly a change from a footballing perspective to bring on Fabregas in his place.
Leicester 0-1 Chelsea
Morata nets his first goal of 2018 just before the half to give Chelsea the lead.
Chelsea look to follow United, Tottenham and Southampton, who have already booked their places in the FA Cup semi-finals.
Leicester City 0-1 Chelsea
That would have been some goal.
And Riyad Mahrez is disappointed not have have scored it.
Willy Caballero screws his clearing kick straight to the Algerian as he comes under pressure from Jamie Vardy.
With Caballero not too far out of position, Mahrez has to take it first time.
But he hooks well wide.
Image source, PALeicester City 0-1 Chelsea
Back under way.
Leicester City 0-1 Chelsea
Not really surprising.
Tiemoue Bakayoko - on a yellow after a poor first half - is hooked for Chelsea.
Cesc Fabregas is on in his place.
Leicester City 0-1 Chelsea
Alan Shearer
Former England striker on BBC One
Chelsea are stretching Leicester and making the pitch so wide that they're struggling to cope. Victor Moses practically has chalk on his boots.
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Anon: How was that Iheanacho's fault when Mahrez was in full control of the ball and lost it?
Thomas: Even though it was poor It wasn't the sloppy pass that lead to the goal it was Mahrez not passing the ball and trying to beat three Chelsea players. He lost the ball but nobody is talking about that.
These two people are exactly correct. Iheanacho lost the ball, but that was not the mistake that led to the goal.
Leicester City 0-1 Chelsea
Alan Shearer
Former England striker on BBC One
Chelsea have controlled that first 45 minutes and have played the game at their pace. They have deservedly taken the lead. Leicester have got to get 10 yards further up the pitch because they are not asking any questions of that back three whatsoever.
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Lee: Great from Willian to set up Morata who finished well but poor play from Leicester sloppily losing the ball and they got punished.
Ed: Willian makes opponents look like they are running up hill, through treacle, with some heavy shopping.
Leicester City 0-1 Chelsea
Ian Wright
Former Arsenal & England striker on BBC One
It's terrible from Iheanacho for that Chelsea goal. If he stays on the pitch I'll be very surprised.
But, for someone who has not scored since Boxing Day, it is a brilliant finish from Morata.
What he did well was his touches were very precise and put him in a good position to beat Kasper Schmeichel.
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Scott: Morata hardly looks like a striker who hasn't scored in 10 games
Shamsheer: Morata scores but that goal is all about Willian's strength, guile & vision.
Leicester City 0-1 Chelsea
Try, try, try and try again.
Chelsea had four shots at goal in that first half - all coming from the boot of Alvaro Morata.
The Spain striker failed to hit the target with two efforts, with a crisp shot straight at Kasper Schmeichel in-between.
But he got his reward in the end with a smart finish that even has Gary Lineker, Alan Shearer and Ian Wright purring. High praise indeed....
Image source, OptaHT: Leicester 0-1 Chelsea
Phil McNulty
BBC Sport chief football writer at The King Power Stadium
Question asked - and answered.
Cool finish by Alvaro Morata and the perfect answer to the rough treatment dished out by Wes Morgan and Harry Maguire.
Brilliant work by Willian for a moment that will do Morata and Chelsea the power of good.
Leicester City 0-1 Chelsea
That is your lot.
Chelsea ahead on the scoreline, but it has been pretty even in all departments.
Just Willian and Alvaro Morata's combination of quality the difference.
Image source, Getty Images#bbcfacup or 81111 on text
Robin: Willian is Chelsea’s best player by a long long way.
Josh: Sheer brilliance from Willian, the difference between the two sides.
Leicester City 0-1 Chelsea
Kelechi Iheanacho is grappled to the floor by Tiemoue Bakayoko and the Chelsea midfielder sees yellow to make the rest of his afternoon a little more difficult.
Leicester 0-1 Chelsea
Phil Brown
Swindon Town manager on BBC Radio 5 live
A great example for young kids watching. Kelechi Iheanacho had two players to pass to and he was sloppy. Before you know it, Chelsea were on the counter attack.
Willian plays a first-class pass, they leave Morata one on one, and the rest is down to the Spaniard. What a great finish.
Leicester City 0-1 Chelsea
Danny Murphy
Former England midfielder on BBC One
It all starts from the lazy, sloppy pass from Kelechi Iheanacho. Chelsea win the ball back from Riyad Mahrez, but it's all about Willian then. Talk about moments of brilliance...
The ability and close control he shows to go past two or three Leicester players is brilliant. He goes past them like they are not there.
Alvaro Morata takes his time and slots it in the corner. A super breakaway.
Alvaro Morata
That counter-attack could not have been slicker if it was dunked in Brylcreem.
Willian slips past Wilfred Ndidi and Ben Chilwell in his own half, eating up the turf with his raking stride.
He gets his head up and threads an eye-of-the-needle pass through the remnants of the Leicester defence to Alvaro Morata.
You can almost hear the knees knocking and cogs whirring as the Spaniard goes in on goal, but he holds it together admirably.
A lovely dinked clip into the far corner for his first goal of 2018.
Image source, ReutersLeicester City 0-0 Chelsea
Tiemoue Bakayoko looks absolutely out of confidence.
He is caught dawdling on the ball and then misplaces a pass.
The Chelsea midfielder needs to hit the reset button over the summer.