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Guilbert pokes in El Ghazi's cross for Villa lead, substitute Iheanacho levels after huge pressure
Winners of two-legged semi play Man City or Man Utd
Villa last won competition in 1996; Leicester in 2000
Second leg on 28 January
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Leicester 0-1 Aston Villa
Clinton Morrison
Former Crystal Palace striker on BBC Radio 5 Live
Villa are finding it comfortable. Leicester are panicking - just relax! There's a long way to go in this match and in the tie. Credit to Villa, they've been brilliant so far.
Leicester 0-1 Aston Villa
The sort of booking you can see coming a mile off. Ezri Konsa clears the ball down the line, Jamie Vardy sprints across to close him down, there's contact after the ball is channeled and Vardy goes into the book.
Leicester 0-1 Aston Villa
Ricardo is quick, eh? He skins Neil Taylor down the line and puts a low cross in but it's well monitored by Tyrone Mings who is able to clear. Villa popping the ball about with more confidence now. Half time is in sight.
Leicester 0-1 Aston Villa
Youri Tielemans has grass to run into, Anwar el Ghazi puts in a lunge and takes him out. In the book you go sir.
Leicester 0-1 Aston Villa
Clinton Morrison
Former Crystal Palace striker on BBC Radio 5 Live
Vardy's making a lot of good runs. He always plays on defenders' shoulders, so get Perez and Maddison into pockets and they'll feed him - and he will eventually put one of those chances away.
Leicester 0-1 Aston Villa
It's offside but all hail the touch from Jamie Vardy as he kills a ball coming over his shoulder brilliantly before firing the shot over the top.
Vardy is 33 on Saturday. He's getting better and better.
Leicester 0-1 Aston Villa
That was Villa's first shot on goal of the night. No need for panic from the hosts but as Phil says the home crowd have gone quiet after that setback.
Phil McNulty
BBC Sport chief football writer at The King Power Stadium
Smoke rises from the corner of The King Power Stadium where there is a cacophony of noise from Aston Villa's fans.
It was against the run of play but Villa will not care. They have something to defend.
Leicester 0-1 Aston Villa
Clinton Morrison
Former Crystal Palace striker on BBC Radio 5 Live
It's great play. El Ghazi does well, causes all sorts of problems on the left-hand side, squares up Soyuncu and gets the ball in - and credit to Guilbert, he wants to score and gets in front of Chilwell and it's a really good finish into the roof of the net.
I thought Villa were coming here for a draw, but they got numbers in the box and Guilbert wanted it more than Chilwell. If you want it more than the defender, then nine times out of 10 you'll get the goal.
Leicester 0-1 Aston Villa
Time to point out that there are no away goals in the semi-finals. If it were to end level on aggregate after 90 minutes in the second leg we'd go straight to penalties.
Frederic Guilbert
Told you a goal was coming!
Totally against the run of play, Villa take the lead. Brilliant goal as well, all started by Jack Grealish carrying the ball from deep. His pass almost finds Anwar El Ghazi but it's well cut out by Caglar Soyuncu.
The ball finds its way to El Ghazi in the end, his cross is nice and wing-back Frederic Guilbert catches Ben Chilwell napping at the far post, meets it on the volley and stabs it home.
Leicester 0-0 Aston Villa
Clinton Morrison
Former Crystal Palace striker on BBC Radio 5 Live
Villa will be happy because they haven't conceded a goal yet! They would have known Leicester would dominate the football, but they've defended well.
Leicester 0-0 Aston Villa
Another dangerous cross from the left hacked away by Tyrone Mings, Villa just about holding it together...
Leicester 0-0 Aston Villa
James Maddison whips another free-kick over the bar from a tight angle. Leicester knocking on the door...
Leicester 0-0 Aston Villa
Over 70% of the ball from Leicester and you can feel a goal coming, maybe. Ayoze Perez plays a lovely ball into the path of Jamie Vardy, he's wide left of the area and goes for goal but Orjan Nyland saves with his knees. A cracking pass.
Leicester 0-0 Aston Villa
Clinton Morrison
Former Crystal Palace striker on BBC Radio 5 Live
Bit of a miscommunication and Vardy's on to it, he's sharp! Nyland nearly made a mess of it, because it wasn't the fiercest of strikes. Villa nearly made a mess there.
Phil McNulty
BBC Sport chief football writer at The King Power Stadium
Leicester having most of the possession and just starting to give Aston Villa one or two alarms but otherwise it has been a quiet start.
The Foxes, as expected, forcing the pace.
Leicester 0-0 Aston Villa
James Maddison's delivery is on the money again but Jonny Evans can only flick a header wide. Marvelous Nakamba then plays a blind backpass header and it goes straight to Jamie Vardy - his shot is pushed out.
Chance!
Leicester 0-0 Aston Villa
Patient, pretty possession from Leicester but Aston Villa are providing stiff resistance. Well drilled so far. Leicester have won a free-kick though for a poor challenge on Ben Chilwell.
Leicester 0-0 Aston Villa
Villa did lose Tammy Abraham back to Chelsea of course, not much they could do about that. They definitely need to sign someone up there soon though.
As it is Anwar el Ghazi attacks down the right and is whistled for a shoulder barge. Soft.