Chelsea's bid for the Premier League title was dented by a late Jarrad Branthwaite equaliser as Everton held the Blues to a 1-1 draw at Stamford Bridge.
Chelsea started with a real intent and ought to have gone in front inside five minutes. Reece James was sent through by a clever Jorginho pass, but the England international could only curl his effort wide of the near post.
Thomas Tuchel was without the services of Romelu Lukaku, Kai Havertz and Callum Hudson-Odoi in attack, but there was no issues in chance creation in the early exchanges.
Mason Mount side footed an effort inches past the post after being threaded through by James before Mount could only back heel the ball into the grateful arms of Jordan Pickford after Hakim Ziyech picked the England international out inside the penalty area.
Ziyech drew another fingertip stop from the Everton goalkeeper and Mount, again, was denied by Pickford just shy of the half-hour mark. Marcos Alonso scampered down the left and when his pull back reached Mount in the penalty area he could only side foot his effort straight into the vicinity of his England teammate.
The Blues then carved out their biggest chance of a remarkably one-sided first half, with Mount once again left with his hands on his head. The midfielder looked certain to score when he was sent through by Antonio Rudiger following a break down from a corner, but Pickford was off his line swiftly to deny Mount with his feet.
Chelsea continued to pour forward after the interval, and went close through an unlikely source in Cesar Azpilicueta. The Toffees failed to clear a James free-kick but, after the ball fell invitingly to the Spaniard, he balooned his effort over the bar.
The Stamford Bridge crowd were beginning to grow restless as Everton squandered a promising counter-attacking opportunity through Alex Iwobi's indecision.
However, Mount eased the Chelsea faithful's worries on the 70th minute mark. With the Toffees stretched, James picked up possession and sent Mount through on goal with acres of space. After spurning several chances in the first half the England international made no mistake this time, curling his effort round a helpless Pickford.
Just as Stamford Bridge began to exhale in harmony, Rafa Benitez's side responded three minutes later. Anthony Gordon flighted a sumptous free-kick towards the far post and 19-year-old Jarrad Branthwaite stuck out his leg to prod the ball past Edouard Mendy to send Chelsea back to square one.
Here's how both teams rated.
Chelsea player ratings
1. Goalkeeper & defenders
Edouard Mendy (GK) - 5/10 - A very quiet evening until he had to pick the ball out of the back of the net in the second half.
Cesar Azpilicueta (CB) - 5/10 - A composed performance, often stepping into the midfield line to help Chelsea progress the ball.
Thiago Silva (CB) - 6/10 - A comfortable evening until Chelsea lost control in the second half.
Antonio Rudiger (CB) - 5/10 - A few of his trademark marauding runs caused Everton problems.
2. Wing-back & midfielders
Reece James (RWB) - 7/10 - A menace for the Everton defenders, constantly floating infield to wreak havoc.
Jorginho (CM) - 6/10 - Orchestrated Chelsea from the heart of midfield, threading a couple of gorgeous through balls.
Ruben Loftus-Cheek (CM) - 4/10 - Didn't put a foot wrong but he still looks an awkward fit as a central midfielder given his insistence to hold onto the ball for too long.
Marcos Alonso (LWB) - 3/10 - Although he produced a few promising cut-backs, Chelsea still miss Ben Chilwell's explosiveness on the left hand side.
Hakim Ziyech (RW) - 6/10 - A bright performance, drawing an early booking for Mason Holgate with his trickery.
Mason Mount (ST) - 8/10 - Arrived in countless promising positions, eventually making Everton pay in the 70th minute.
Christian Pulisic (LW) - 5/10 - Linked play effectively with Mount and Ziyech, but he barely made an impact in the penalty box.
Ross Barkley (CM) - N/A
Saul Niguez (CM) - N/A
Trevoh Chalobah (CB) - N/A
Everton player ratings
5. Goalkeeper & defenders
Jordan Pickford (GK) - 8/10 - Huge save to deny Mount in the first half and looks back to his best.
Mason Holgate (CB) - 4/10 - Booked for an early lunge on Ziyech and endured a difficult evening.
Michael Keane (CB) - 6/10 - Marshalled Everton's defence and grew in confidence as the game went on.
Jarrad Branthwaite (CB) - 9/10 - A baptism of fire, but the 19-year-old played with remarkable composure and was rewarded with a dream goal in the second half.
6. Wing-backs & midfielders
Jonjoe Kenny (RWB) - 4/10 - Barely ventured into the Chelsea half but, after an uncomfortable opening period, he improved as the game wore on.
Andre Gomes (CM) - 4/10 - He would have preferred to see more of the ball, but he was nevertheless diligent in his defensive duties.
Abdoulaye Doucoure (CM) - 7/10 - Didn't see much of the ball but he was incredibly effective at regaining possession and driving his side forward to relieve pressure.
Ben Godfrey (LWB) - 5/10 - An unfamiliar role for the former Norwich man but he rose to the challenge.
Alex Iwobi (RW) - 2/10 - Struggled to get involved in the game and was easily marshalled by Rudiger.
Ellis Simms (ST) - 4/10 - A big opportunity for the 20-year-old, but he was largely isolated throughout.
Anthony Gordon (LW) - 7/10 - More influential than Iwobi on the opposite flank, causing Chelseaa few concerns with his pace in behind.
Lewis Dobbin (ST) - N/A
Jean-Philippe Gbamin (CM) - N/A
Tyler Onyango (LW) - N/A