There were only 2,000 Evertonians inside Goodison Park but what an influence they had.
And what a din they created when Gylfi Sigurdsson scored the only goal of an absorbing match after 22 minutes.
Sigurdsson converted from the spot after Dominic Calvert-Lewin was fouled by Edouard Mendy and the goalscorer, playing as an authentic Number 10, was a deserving matchwinner.
Opponents don't come much tougher than Chelsea right now and Everton had to work for everything they got: the early supremacy, opportunities on the counter-attack and their first clean sheet since the opening day win at Tottenham Hotspur.
The home team were helped from start to finish by their supporters. First they were urged onto the front foot as Everton set about Frank Lampard's team, then roared over the line as Carlo Ancelotti's side defended magnificently.
They crowded behind the ball, tackled and closed spaces. As legs tired, Ancelotti sent on Tom Davies and Jonjoe Kenny, employing a back five to manage the closing minutes.
Chelsea boast the division's second best defensive record, so were never going to concede in numbers. They are second highest goalscorers, too, so Everton needed a stroke of fortune to come through unscathed and the visitors twice hit the woodwork.
Calvert-Lewin didn’t score Everton’s goal, which counts as a surprise right now.
Seven times this season, he’s been Everton’s first goalscorer.
He had a hand, though. Of course he did.
Calvert-Lewin tamed Jordan Pickford’s forward kick, advancing into the area where he was met by Mendy.
The Chelsea keeper knew who had the ball and wanted to clear up the problem for his side, despite a number of defenders in attendance.
Calvert-Lewin got to the ball first, though, nudging it on with the sole of his agilely-raised right boot.
Mendy had nowhere to go and the collision was inevitable.
So, too, the decision of Jon Moss, the referee, to point to the spot – for the 1,000th penalty in Everton league fixtures.
This wasn’t one of those awards which needs examining by the VAR.
All that needed determining from here was who would take the kick.
Richarlison and Sigurdsson were both keen on the job. Sigurdsson got it and rolled his finish to Mendy’s left.
Every outfield player joined a tight huddle to celebrate inside Chelsea’s penalty area.
Everton led 1-0 and that felt about right.
The home team were quicker and hungrier in the opening 20 minutes.
Driven on by 2,000 supporters who made far more noise than should be possible, Everton chased and closed and urgently passed the ball.
If Chelsea reached the hosts’ penalty box, they had the door slammed in their face.
Ben Godfrey set the tone by blocking from Reece James after Chelsea swept forwards from left to right on two minutes.
Soon after, Richarlison, marauded infield from his left flank, carefully feeding a pass to Sigurdsson.
He sent a return pass round the corner but Richarlison’s low effort was easily held by Mendy.
Chelsea right-back James twice came close to equalising.
James was the player fouled by Richarlison as he surged forwards two minutes after Everton's goal.
The free-kick was 25 yards out and struck hard towards the right corner by the England player.
Pickford, though, took off to palm the ball behind for a corner.
The set-piece was partially cleared and there was James again, on the left edge of the box.
His shot cracked the base of Pickford’s right post and spun across goal and behind on the opposite side.
Moss initially signalled a goal-kick but changed his mind to give Chelsea a corner, suggesting Pickford applied a crucial touch.
The system employed by Ancelotti lent itself to the counter as a profitable route of attack.
Indeed, in the opening half, Chelsea had nearly three-quarters of the ball.
When Everton gained possession in their own half, they sought to exploit the space left behind by the pressing away team.
Alex Iwobi, excellent on the right, sped forwards five minutes before half-time, steering a pass inside for Sigurdsson – going at full-pelt himself after recovering possession close to his own penalty area.
The Icelander helped the ball on first time for Richarlison but his low attempt was palmed out by Mendy, Thiago Silva first on the scene to tidy up.
Chelsea had created two further openings by this point.
Olivier Giroud headed Ben Chilwell’s free-kick from the right back across goal.
Kurt Zouma was the recipient 10 yards out but snatched at the chance and Pickford saved comfortably.
Mason Holgate, playing at right-back – with Everton reverting to a four-man defence – applied the pressure when Timo Werner sized up an effort from Mateo Kovacic’s delivery.
Werner never appeared comfortable and struck too high to bother Pickford.
Mason Mount was closer – but still too high nonetheless – 60 seconds after the restart.
Mount had to pop the ball over Pickford – recovering his ground after racing out to punch clear – and four defensive bodies.
He lifted it over the lot of them but the ball dropped on the top of Pickford’s net.
Richarlison versus Mendy was a recurring duel.
Sigurdsson was perfectly placed to pick up a ball which cannoned off Yerry Mina, blocking from Kai Havertz, and advance with N'Golo Kante in pursuit.
Richarlison received the pass towards the left of the box and sent a shot skidding towards the right corner.
Mendy saw it late but made a smart intervention to turn the ball behind.
Mina was over from a Sigurdsson cross, then Sigurdsson’s free-kick from 25 yards dipped too late to avoid the same destiny.
James angered the home players and supporters with a challenge on Calvert-Lewin which saw him booked.
Moss whistled for another penalty when Calvert-Lewin was brought down by Chilwell.
This did require VAR, though. No question about the infringement.
But Calvert-Lewin was offside when he sprinted onto Iwobi’s forward prod.
James stepped in to stop Richarlison having a free run at goal and on the same flank an exceptional piece of defending from the outstanding Ben Godfrey denied Werner the opportunity to escape.
The pattern of Chelsea possession and Everton seeking chances to break continued.
Abdoulaye Doucoure covered an awful lot of ground to try to get on the end of an Iwobi delivery but couldn’t make contact.
Doucoure conceded a free-kick tracking back 10 minutes from the end.
Mount’s dead-ball strike flew into Pickford’s left post and raced out of harm’s way.
That was as close as Chelsea would come. Five minutes of added time were expertly handled by the hosts. This was a night when Everton got what they deserved.
Gylfi Sigurdsson wears 10 on his back but opportunities to play in a traditional Number 10 role since joining Everton have been thin on the ground.
The Icelander, then, relished the task of providing a link between midfield and Dominic Calvert-Lewin up front.
Sigurdsson provided six of Everton's seven chances. It is the highest number of opportunities created by an Everton player in a Premier League match for more than two years.
He was busy off the ball, too, retreating to mark N’Golo Kante, Chelsea’s deepest lying midfielder.
His chasing to prevent Ben Chilwell clearing down the line in the opening minute elicited an appreciative roar from the Howard Kendall Gwladys Street End.
When Richarlison wanted help to fashion space in the box on six minutes, he found an ally in Sigurdsson, available with his back to goal and steering a return pass for the Brazilian to shoot.
Playing in his favoured position and wearing the captain’s armband, Sigurdsson was high on confidence.
Richarlison fancied the penalty awarded to Everton midway through the opening half.
But Sigurdsson invoked skipper’s rights and made the job of scoring Everton’s first goal in front fans since 1 March look very straightforward indeed.
On 40 minutes Sigurdsson trawled all the way back to 25 yards from his own goal to slide in and prevent Timo Werner from receiving a pass to feet.
Everton broke and there he was again, Sigurdsson in the other half now, transferring the ball from Alex Iwobi to Richarlison for a strike kept out by Edouard Mendy.
Sigurdsson was enjoying this.
He left Kante trailing to set up an opportunity for Richarlison, then sent in a terrific cross from the right which Mina couldn’t keep low enough to trouble Mendy.
A Sigurdsson free-kick from 25 yards travelled fractionally over.
Right up until his exit with eight minutes remaining – he was afforded a standing ovation – Sigurdsson was knitting together Everton’s play, measuring passes and collecting loose balls.
It was a tremendous night’s work.
Evertonians Make The Difference
From the moment Jordan Pickford marched towards the Howard Kendall Gwladys Street End at 7.11pm this felt different.
The Evertonians spread out behind the goal where Pickford would go through his warm-up were already on their feet and the applause sent a shiver down the spine.
It was comforting to hear those sounds synonymous with going to the football after more than nine months when Goodison Park has been off-limit for fans.
That chorus of the team name which reverberated around the stadium when Everton’s outfielders joined their goalkeepers on the field hadn’t been heard here since 1 March.
Ten Goodison Premier League games have come and gone without supporters being allowed in.
The rousing ovation as Everton’s players congregated on the touchline to conclude their preparations, then, was a long time in the making.
Shut your eyes when Z-Cars blasted out and you could have been kidded into believing there were 20,000 and not 2,000 in the ground.
Hearing the announcement of each player’s name greeted with a cheer rather than eerie silence was refreshing.
We knew already how Evertonians can spur their team.
But 2020 has taught us you don’t know what you’ve got until it’s gone.
A tackle or interception, or the sight of an Everton player charging 20 yards to close an opponent, being met by a blast of approval produces a different occasion altogether.
Carlo Ancelotti was moved to say football felt like a different sport without fans and here was why.
Everton were given a fabulous send off at half-time. This one was delivered in the moment, a response to a gutsy and intelligent and skilful performance.
Ancelotti got to hear his Carlo Fantastico song again, too, the manager’s name enthusiastically sung just before the hour.
The sounds grew more intense as Everton resisted Chelsea pressure and there was an audible groan when five minutes off added time was signalled.
When that period elapsed and the celebrations and songs broke out, things felt normal again.
Perfect Platform For Busy Run
Carlo Ancelotti insisted the return of supporters would aid Everton’s bid to regain their footing on home turf.
Everton’s opening three home games this season brought seven points and 11 goals.
They came into this following a stumble, though.
And after losing two in succession at Goodison, they couldn’t have been handed a tougher ask to avoid a third defeat.
Chelsea arrived unbeaten in 17 matches. They’d not lost in nine in the Premier League.
Everton would need a “top, top” performance to win, declared Ancelotti.
And that’s exactly what they delivered.
This was excellent in every respect, Everton solid defensively, fast and strong in midfield and dangerous up front.
Jordan Pickford in goal was excellent.
This was precisely the result and display Ancelotti wanted at the outset of the season’s busiest period.
Everton began a run of six matches in 16 days here.
It is often said that footballers can’t wait for the next game when they’re winning.
Ancelotti pointed to Everton's 100-per-cent record of success in their opening seven matches when rest was at a premium, as reason for optimism ahead of this rush of fixtures.
On this Saturday night in December, Everton sit seventh, two points behind third-placed Chelsea and only four points off the top.
Leicester next on Wednesday and what a test that will represent, before Arsenal are at Goodison in seven days.
But Everton will enter a busy week and hectic schedule in a good place – both in the Premier League and mentally following one of the most impressive displays of Ancelotti’s year in charge.