Teenage defender Jarrad Branthwaite netted his first Everton goal to plunder a draw for the injury-hit Toffees, stunning a Chelsea outfit missing a clutch of senior players through Covid-19.
Mason Mount thought his seventh top-flight goal of the campaign would be enough for Chelsea to mask a major glut of missed chances.
Reece James produced his sixth assist of an already-fine campaign, but no sooner had the Blues forged ahead than Branthwaite turned in Anthony Gordon’s free-kick to silence Stamford Bridge.
Chelsea’s fourth match in seven without a win in the Premier League left Thomas Tuchel’s men trailing leaders Manchester by four points.
The Blues had lost Romelu Lukaku, Timo Werner and Callum Hudson-Odoi to positive Covid tests in the build-up to Thursday’s west London clash.
Ben Chilwell had also returned a positive test but was already out with knee trouble, while Mateo Kovacic should complete his isolation after Covid on Friday.
Kai Havertz missed out due to illness, but was still awaiting the results of tests to determine whether his issue would turn out to be coronavirus.
Rafael Benitez’s sorry Everton arrived with just one win in 10 Premier League encounters and were besieged throughout a torrid encounter.
And yet the Toffees still came away with a highly creditable point, whatever their fortune.
Chelsea were left to lament a match full of wretched finishing, and a definite misstep in the Premier League title race.
Chelsea could easily have been 6-0 ahead by half-time.
The irrepressible James somehow sidefooted wide when played through by Jorginho, before Mount dragged just across goal.
Hakim Ziyech left the outclassed Mason Holgate for dead on the spin, then James forced Jordan Pickford into a full-stretch save from a fine free-kick.
James then thundered a snap shot just over the bar after Marcos Alonso’s free-kick rebounded off the wall.
Ziyech shot wildly high and wide on the left flank, then Mount failed to connect properly with Alonso’s cross to gift Pickford an easy save.
Morocco forward Ziyech scuffed wide from the edge of the area, and then Mount saw a low effort rebuffed by Pickford’s boot.
Pickford tipped round the post from Mount to open the second half, before Ruben Loftus-Cheek flicked over the bar from Alonso’s corner.
Cesar Azpilicueta hooked high over the bar after Everton failed to clear James’ whipped cross from a free-kick.
Antonio Rudiger had his head in his hands after nodding wide from another teasing James free-kick.
As the hour-mark passed and Chelsea gawped in frustration at their litany of botched chances the hosts knew only calmness and renewed focus would break the deadlock.
Just when the night started to become niggly though, Chelsea broke at pace and James sent Mount in on the right.
The England star beat the defence with his run before slotting past Pickford, to cut the Stamford Bridge tension and hand the Blues a majorly belated lead.
The Blues’ relief quickly turned into rancour, however, as Branthwaite poked home Gordon’s whipped free-kick.