Chelsea dominated possession but came unstuck as their nervy defence was unlocked by a gritty and determined Everton
IF Maurizio Sarri is to take Chelsea into the Champions League next season, it looks as though he will have to do it via Baku.
They certainly need a miracle to get in the Premier League’s top four.
Defeat at Goodison Park, due to an excellent second half from Everton, now means Chelsea remain three points off Arsenal.
It also raises more questions over this Chelsea side, with Sarri suggesting his players are suffering from a “mental block”.
Sarri said: “I’m worried about our mentality. I think the situation is clear.
"We played probably the best 45 minutes of the season then, suddenly, at the beginning of the second half, we stopped playing. I don’t know why.
“So the situation is clear. It is impossible the problem is a physical problem because if you have a physical problem, you go down gradually, not in one second.
“We played really very well until the last minute of the first half and then suddenly very badly in the first minute of the second half.
“It’s very difficult for players to explain to me the change. Very difficult for me to explain to you the change, probably it is a mental block I think.”
All eyes are now on their Europa League quarter-final with Slavia Prague as they look to win a tournament which will see the final staged in Azerbaijan.
But do not put any money on them. As this performance proved, Sarri’s team is so unreliable which is why the manager is unlikely to be here next season.
Chelsea were much the better team in the first half only for Everton to seal the match with goals from Richarlison and Gylfi Sigurddson, via a rebound after his missed spot-kick.
It was the most important win of Marco Silva’s spell as manager but was also a forgettable return to the club for Ross Barkley
He was jeered, suffered a nose bleed and was then booed off the pitch when being replaced – while he also clapped the home fans sarcastically.
After a rough few weeks, there was also a ninth clean sheet of the season for England keeper Jordan Pickford and he made some important stops.
Yet seven minutes had gone and Chelsea could have been 3-0 up.
Pickford got down low to his right and displayed a strong arm to keep out an early strike from Eden Hazard.
And when Pickford was beaten by a deflected shot from Hazard, he was saved by the post. Incredibly, it was the 20th time Chelsea had hit the woodwork this season.
With Everton’s defence all over the place and extremely passive, Gonzalo Higuain showed an outstanding first touch but not so good finish when he was clean through although Yerry Mina at least made his presence felt.
The early pressure stopped but Pickford needed a second attempt to gather a shot from Jorginho after more quality football from Higuain.
Chelsea fans were singing: “Ross Barkley, you left coz you’re s***” and he was jeered when teeing himself up for a shot – and then cheered as the effort sailed harmlessly into the arms of Pickford.
And there was also a free-kick from Barkley which was also greeted with cheers as he hammered it into the wall.
Dominic Calvert-Lewin should have done better to get a header on target and at the other end, Pedro delivered a polished finish on the strike of half-time but was correctly ruled offside.
As Everton started the second half brightly, Kepa was forced into making his first crucial save, batting away a good effort from Gomes.
But there was nothing he could do soon when Richarlison opened the scoring with Silva’s team looking unrecognisable from the first half.
Calvert-Lewin, unlike his effort before the break, managed to control a header from Gylfi Sigurdsson’s corner and the ball rose perfectly for Richarlison who nodded the ball from a couple of yards.
It took Chelsea far too long to wake up although they eventually sorted themselves out.
Marcos Alonso stuck a drive into the sidenetting and Pickford came to the rescue again with another good low stop to deny Higuain.
Barkley suffered a bloody nose, had a shot blocked by Michael Keane and soon after was then replaced by Ruben Loftus-Cheek.
Yet it got worse, rather than better for Chelsea.
Alonso caught Richarlison for the penalty and while Sigurdsson missed his third spot-kick of the season with Kepa diving the right way, the rebound fell perfectly – and the Icelandic international had an easy chance.
Calum Hudson-Odoi was brought on and made a decent impact while Pickford tipped over a half decent effort from the youngster.
Everton’s Theo Walcott was given a run-out 24 hours after turning 30 but was denied a goal with a good save from Kepa.
For once, Everton's fans went home happy.
