Jamie Vardy launched the Puel era with an early opener before Jonjoe Kenny sliced an attempted clearance into his own net to double Leicester's advantage. It was ruled as Demarai Gray's goal, but Kenny's intervention was decisive.
Leicester were a revitalised and menacing counter-attacking unit, troubling Everton with their pace and directness throughout as the King Power bounced with joy at the sight of some free-flowing attacking football.
For interim Everton boss David Unsworth, the game produced more questions than answers unfortunately as the Toffees continue to languish in the relegation zone, having picked up just eight points from ten games.
The table has a more positive complexion from a Leicester perspective already, as the Foxes climb up to 11th, four points clear of the relegation zone.
Here are five key takeaways from the game.
Unsworth's Speedy Toffes Doesn't Come Off
One of the most consistent criticisms of Ronald Koeman's Everton was the lack of pace in the team. Unsworth has been listening. Lining up with Kevin Mirallas and Aaron Lennon on the wings, as well as the sprightly Tom Davies in the middle, there was a concerted effort to inject some acceleration into Everton.
Although it was a slow start, Lennon, making his first league start since January, proved what he offers Everton. Rooney slipped an incisive through-ball to the wide man, who had run off Christian Fuchs. The former Tottenham Hotspur favourite pulled the ball back to Dominic Calvert-Lewin, who couldn't quite connect.
Lennon has made a career of making those angled runs off full-backs and, while he is 30 and may have lost half a yard of his blistering pace, he offered a glimpse of how he can still penetrate defences and get in behind, something Everton have really lacked this season.
While both Lennon and Mirallas were subbed at half-time, there was a bit more zip to Everton when they had the ball.
Glorious Gray Takes Chance To Shine
There were two moments early on in which Gray, who was frustrated at the lack of starting opportunities under both Claudio Ranieri and Craig Shakespeare, ran in behind a dozing Leighton Baines and delivered dangerous crosses.
That should have been ominous for Everton but they did not heed the warning, as the 21-year-old produced a devastating surge forward to create the opener, flying past three men before slotting a through ball to Riyad Mahrez, who crossed to Vardy.
It was a thrilling snapshot of what Gray is capable of and, combined with the pace of Vardy and Mahrez, it proved a real handful for the Everton back-line. Gray was also involved in the second goal, delivering the cross which forced Kenny to hash his attempted clearance straight past Kasper Schmeichel.
The winger was an effective outlet on the right and it certainly won't have gone unnoticed by his new manager, who is of course still figuring out his best starting eleven but, with performances like this, Gray is certainly staking his claim.
Mirallas Can Still Be A Factor At Everton
The Belgium international has been at Everton for five years now and, while he's shown flashes of brilliance at times, he hasn't always been assured of a starting berth. That was the case under Koeman, who mainly used the 30-year-old from the bench.
However, as shown here, Mirallas is a purposeful and single-minded attacker. He is always looking to move defenders and shoot when he gets the opportunity. He came close with two efforts in the space of the minute in the first-half, one flashing just wide before forcing a fingertip save from Schmeichel with the other one.
While he can be frustrating and enigmatic, he can still be effective, as long as he stays fit and maintains a strong working relationship with Unsworth, or whoever ends up in charge. It didn't quite work out for him at the King Power as he was hooked off at half-time, but that doesn't necessarily have to be a death knell for his Goodison Park career.
He has been given chances before without impressing on a consistent basis, though, so it would be reasonable to assume that this is his last chance. Despite only lasting half the game, it must be worth something that he came closest to Everton scoring while he was on the pitch.
Claude's Counter Works A Treat
Leicester emerged as one of the league's most devastating counter-attacking teams when they romped to a historic title triumph under Ranieri, and that continued – albeit to varying degrees of success – under Shakespeare.
Recognising that Everton are a team that usually enjoy the majority of possession, Puel started Gray to give Leicester that blistering burst on the break, and it paid off wonderfully, with the winger's acceleration proving crucial for the first goal.
With a two-goal cushion, the Foxes were content with allowing Everton to have the ball and spring counters whenever possible. That was clear just two minutes after the break when Gray found Mahrez down the left channel. Had the Algerian not post possession, Leicester would have found themselves in a very promising situation once again.
As expected, Everton dominated possession, but Leicester still managed more shots on target and looked the more likely to score.
Rooney Still Everton's Most Creative Player
Despite splurging close to £70million on Gylfi Sigurdsson and Davy Klaassen, Rooney was the one providing the creative edge as the former watched from the bench while the latter didn't even make the squad.
While Sigurdsson and Klaassen fight for their Everton careers, Rooney always looked most likely to unlock the Leicester defence.
He did so perfectly, of course, slipping a fine through ball to Lennon to create a clear-cut chance, while a clipped cross to the far post picked out substitute Oumar Niasse, whose first touch let him down. The failure of Niasse, and indeed Calvert-Lewin – without a goal this season – to apply convincing finishing touches only further highlights Everton's need for a clinical finisher.
Rooney, now 32, perhaps didn't expect to play such a prominent role in the first-team following Everton's heavy summer spend but he is doing more to prove his worth than most. It's important not to forget that he is also the Toffees' top scorer, with four goals to his name already.
Wayne Rooney's game by numbers vs. Leicester:
82% pass accuracy
50% aerial duels won
2 chances created
Trying to create. pic.twitter.com/LhrqfRrIB6
— Squawka Football (@Squawka) October 29, 2017
Sigurdsson replaced him with just under 20 minutes remaining and, unfortunately for Everton, was unable to make much of a meaningful impact. In fact, after Rooney's departure, Everton lacked a creative spark and Sigurdsson skirted about in anonymity during his 20-minute cameo.
Tom Davies, while possessing industry and spirit, seems to lack cutting edge and quality in the final third. He played the full 90 minutes and couldn't come close to opening up Leicester's defence.
It was the same old story for Everton. They had 59 per cent possession and had 140 more passes than Leicester with 466, while the 16 shots was the second-highest they've managed this season, but a lack of a telling touch in the penalty area cost them once again.