Everton suffered another defeat, their fifth in the last six games in all competitions, as David Unsworth was unable to spark a revival in the team's fortunes at Leicester.
The Blues fell behind after 17 minutes when they were caught on a lightning counter-attack by the Foxes and Riyad Mahrez crossed low for Jamie Vardy to sweep home.
Disaster then struck for young fullback Jonjoe Kenny when he sliced Demarai Gray's attempted cross past Jordan Pickford, leaving Everton with a mountain to climb for the remaining hour of the game.
Unsworth had named a similar line-up to the one that started at Chelsea in the League Cup in midweek, with the exception of Idrissa Gueye returning from suspension to replace Beni Baningime in midfield and Dominic Calvert-Lewin in the starting XI in place of the injured James McCarthy.
Everton were sloppy in the early going, however, and Gray sounded a couple of warning shots with dangerous crosses, one of which Ben Chilwell scooped over the bar from around the penalty spot.
When a poor free kick from Leighton Baines was cleared, however, Leicester broke, with three Everton players a failing to prevent the breakaway and Vardy was the eventual beneficiary to open the scoring.
Mahrez might have done better with a clear shot on goal after holding off Ashley a Williams but fired straight at Jordan Pickford before Wayne Rooney threaded a beautiful pass in for Aaron Lennon but the winger chose to try and cut it back for Calvert-Lewin rather than shoot and the chance went begging.
Two minutes later, it was 2-0 when Kenny's unfortunate error compounded Everton's problems but they were denied the chance to halve the deficit by a horrible error of judgement by referee Andre Marriner. Lennon appeared to be fouled in the penalty area without the defender touching the ball but the official waves play away despite being well-placed.
Kevin Mirallas then twice went close, smashing one effort a foot wide of goal and seems another tipped behind by Kasper Schmeichel but while he seemed the most likely player in gray to make a difference, the Belgian didn't reappear for the second half.
Unsworth elected to replace him with Oumar Niasse and throw Beni Baningi,e on for Lennon at half time. The result was a more solid, dominant second 45 minutes from the Toffees' perspective but they carried almost no goal threat.
Rooney' chipped pass found Niasse in the box but his first touch was clumsy and carried the ball through to the goalkeeper while Gueye's speculative effort deflected over and a Phil Jagielka overhead kick following a corner was safely gathered by Schmeichel.
There was plenty of commitment and possession for Everton but almost no more clear-cut chances and Leicester ultimately held on for what was their third successive win in all competitions and their first in the Premier League under new boss Claude Puel.
For Unsworth, while his first audition at Stamford Bridge offered hope, this result will have brought home some stark realities about the Blues' situation as they remain in the bottom three.
Mirallas, Lennon and Rooney provided the attacking strength behind Calvert-Lewin in David Unsworth's first team selection at Leicester but it would not be anything like enough to match the home side's tremendous speed on the counter, Vardy scoring with ease.
Klaassen, Sandro and Vlasic were absent, with Schneiderlin and Sigurdsson on the bench. Keane was in hospital after a nasty gash on his leg became infected.
Everton kicked off and Baines swung in an early cross although things were a little scrappy, Davies giving the ball away and Gray firing wide. Calvert-Lewin had a good tussle with Maguire but fouled him.
The Foxes got Gray loose down the right and Williams had to concede the corner and it needed some defending, Morgan's shot deflected behind by Williams. It was defended out but Gray did the same thing with and even better cross that was driven over. They then switched sides and cut through again, giving Everton some early warnings.
Everton finally had some midfield possession but looked a little disjointed and could not penetrate forward. Davies at least tried a forward pass but it was too long. Mahrez went down with a head injury in an accidental collision off the ball with Gueye.
From an Everton free-kick, The Foxes screamed forward and sliced Everton apart, Vardy completing a devastating move, Gray beating three players, Mahrez,crossing to him first time. Shockingly simple.
Vardy got past Davies, who pulled him back for an early yellow card as Unsworth's charges were in sad disarray after that stunner. Mirallas tried to run through the Foxes defence but, once he lost the ball, another rapier-like attack was on for the home side.
Rooney fouled Iborra but only got a talking to. Slow build-up saw a brilliant ball from Rooney play in Lennon who might have shot but tried to set up Calvert-Lewin, who was not strong enough to command the ball that was flicked out of his path.
But disaster struck as Kenny sliced a horrible own goal in off Gray's cross, a very poor schoolboy error... things could not possibly be worse for poor David Unsworth, although the goal was later awarded to Gray as his cross was deemed to be on target.
At the other end, Lennon was brought down by Fuchs but no penalty said Marriner, perhaps because Lennon was not in possession of the ball, but it looked clear cut on the replay.
Mirallas pulled off a fine snapshot that curled just wide of Schmeichel's post. Rooney worked the ball to him again and he fired past the other post this time, winning a corner. Davies and Calvert-Lewin got in each other's way and the Foxes looked to break again but Davies won a free-kick that Rooney fired in deep to the far post, winning another corner that was cleared.
Rooney was pushed deep but still tried to cross, a little too easy for Schmeichel to collect. Everton were pressing but being too deliberate and slow, trying to rely on intricate passing through a dense Leicester defence. They were probing and poking but not really getting close, and always wary of the Foxes on the break.
Another slow build-up move went nowhere as Rooney lost the ball and fouled in frustration... Sigurdsson and Niasse on for Rooney and Mirallas at half-time? No, it was Lennon and Mirallas off for Niasse and Beningime. So much for the old guard providing width!
Davies got forward and won an early corner that Baines delivered well enough but the Foxes break was stalled this time. Everton were fighting hard but looked scrappy and were trying many things that simply did not come off going forward.
Rooney picked out Niasse brilliantly and he should have done a lot more than simply pass the ball to Schmeichel from a very threatening position. Davies tried to play in Calvert-Lewin but it was intercepted too easily. Jags stopping Vardy from advancing.
It was helter-skelter stuff in midfield as Everton tried to get a grip on the ball but it was desperate at times, Fuchs almost scoring direct from a throw-in, Pickford having to punch it away late. The ball came through to Vardy who was caught by Williams on the shin after he shot wide.
Rooney set up Gana for one of his typical strikes, this one on target but deflected behind for a corner that was cleared. Ponderous pressure from Everton saw Niasse shoot well wide. Niasse then lost out in a tussle with Morgan but Everton were keeping the pressure on the home side.
Beningime played a beautiful ball for Calvert-Lewin to get forward but Niasse was blocked for the cross and Jagielka tried a far too demanding overhead kick.
Another strong attack saw Niasse's shot blocked for a corner. Everton kept pressing but could not create a real chance. Kenny won a corner after the lineswoman was overruled by Marriner, and Sigurdsson replaced Rooney and launched the corner a little too high and deep.
In a rare Leicester attack, Jagielka took out Vardy who jumped up and took the ball on, but Marriner called it back and Pickford punched away the free-kick. Everton got forward but Niasse fired way too early, high and wide.
There was no lack of effort or commitment from the Everton players who were fighting like tigers for every ball, but the composure, skill, and finesse was sadly lacking as they struggled manfully to get back into the game.
Vardy got past Jagielka but Williams was across quickly to deny the Leicester marksman. Beningime gave Chilwell a good run down the left, concedeing a corner, as Albrighton replaced the Leicester player.
Niasse did well down the byeline and won yet another corner off Morgan, Sigurdsson again looping it in high, Schmeichel punching out. But Leicester got forward and Vardy's cross was almost converted by Iborra.
Another Everton attack and more naivety from the ever willing Niasse, his flick to no-one. Kenny's cross and then Calvert-Lewin's shot were blocked but Baines curled his a few inches over.
Plenty of effort for no return and Unsworth was a forlorn sight as he ruminated on another defeat.
Leicester: Schmeichel, Simpson, Morgan, Maguire, Fuchs, Mahrez (75' Okazaki), Ndidi, Iborra, Chilwell (83' Albrighton), Gray, Vardy (89' Iheanacho).
Subs not Used: King, Hamer, Dragovic, Slimani.
Everton: Pickford, Kenny, Jagielka, Williams, Baines, Mirallas(46' Beningime), Davies [Y:20'], Gueye, Lennon (46' Niasse), Rooney(74' Sigurdsson), Calvert-Lewin.
Subs not Used: Robles, Schneiderlin, Holgate, Lookman.
Referee: Andre Marriner.
*UK clocks go back an hour on Sunday morning
Everton and David Unsworth travel to Leicester this Sunday looking to build on their performance against Chelsea in the cup and improve their standing in the Premier League.
The result in midweek may not have been a favourable one but there were signs to support the belief that the Blues are a far better team than they appeared to be in the final weeks of Ronald Koeman's reign — now they have to put a run together and prove it.
If Unsworth was on a hiding to nothing at Stamford Bridge, the King Power Stadium will be where the rubber meets the road for the caretaker manager. With a few more days under his belt to become more familiar with the entire squad and impress on them his methods, he will feel more ready for this his first Premier League game in charge.
As the build-up in the media will surely highlight, this is a meeting between two teams who made poor starts to the new season and whose impatient boards took decisive action in removing their manager as a result.
Koeman was dismissed after nine, Leicester sacked Craig Shakespeare just eight games into the campaign but the Foxes installed their new man this week, with ex-Southampton boss Claude Puel their somewhat surprising choice to take the team forward.
The Frenchman was accused of defensively-minded football at St Mary's which won't necessarily mesh with the attacking philosophy instilled under Claudio Ranieri that swept them to the title two seasons ago. Nevertheless, Everton should be wary of any “new broom” effect Leicester may exhibit of their own.
Puel is expected to make a winning start on Sunday, with the Foxes priced at 11/10 to defeat Everton. The visitors can be backed at 12/5, with the draw available at the same price, but play online casino games ahead of the match to give yourself the chance of boosting your bankroll.
“We'll do our homework as we normally do,” Unsworth said in his pre-match press conference. “We'll be very thorough and detailed in our preparation, regardless of whether there'a a new manager there or not.
“I want us to concentrate on ourselves and do what we do best. That's the most important thing at the moment.
Asked if he felt it was difficult parsing a starting XI from the pool of players he has at his disposal, some of them big names or with big transfer values who, like in midweek, might not get a look-in.
Indeed, the Blues' record signing, Gylfi Sigurdsson, didn't make the pitch at all against Chelsea in the League Cup defeat and neither did Michael Keane. Davy Klaassen and Sandro Ramirez weren't in the match-day squad at all but Unsworth will find in the coming games — depending on how long he remains in the job, of course — that he may need to draw on a number of players while he tries to find the best team and combination.
“No, it's not difficult at all,” he said. “They're nice problems to have. Like I say, we'll do our homework on Leicester and we'll pick a team to win the game with the individuals we have available.
“So, no, it's not difficult working with top talent. I just have to get my message across quickly of how I want to play and so far the players have been fantastic in taking on board that information.
“Today was an outstanding [training] session. Most of the players who played the other night just had a recovery session so the players who weren't involved trained and that was a really decent session.
“The more time we can get on the training ground, the more it will benefit us in the long run.”
Quite what the “right” team to take on Leicester in Unsworth's mind remains to be seen. Idrissa Gueye is eligible again after serving his one-match ban for the two yellow cards he picked up in the defeat to Arsenal while Morgan Schneiderlin is likely to have recovered from the illness that kept him out of the Carabao Cup game.
One of those could come in for Beni Baningime — it would be harsh on the youngster given his impressive debut on Wednesday, but experience might win out — while the other could also start given Unsworth's penchant for two holding midfielders at Under-23 level, although James McCarthy can fill the same brief and may keep his place.
In defence, Ashley Williams's place is, perhaps, the only one under threat following his lapse against Chelsea and Keane could be the beneficiary if Unsworth is so inclined. Meanwhile, in attack he may look to address how isolated Wayne Rooney was and perhaps pull him back into a more withdrawn role or play him off Dominic Calvert-Lewin, either at the expense of a winger or one of his central midfielders.
Leicester have won both their games since Shakespeare's dismissal, a 2-1 victory at Swansea City and a 3-1 League Cup triumph over Leeds, but with both sides in unfamiliar territory when it comes to the man in charge in the technical area, there is opportunity here for Everton to take the positives from Wednesday and carry them through to this game, particularly if Unsworth is able to execute on his game plan.
If they can remain tight at the back by keeping the likes of Jamie Vardy, Shinji Okazaki and Riyad Mahrez quiet, then they will have the platform on which to express themselves in an attacking capacity and, hopefully, find their scoring form up front.
Kick-off: 4pm GMT*, Sunday, 29 October, 2017
Referee: Andre Marriner
Last Time: Leicester City 0 - 2 Everton
*UK clocks go back an hour on Sunday morning