As chaos reigned and reverberated across the Premier League, with players testing positive, coaches demanding circuit breakers and fixtures falling like dominoes, Everton somehow stood firm against all the odds at Stamford Bridge.

It is hardly an exaggeration to claim Rafael Benitez’s embittered side were under siege for almost every minute of this draw, finally succumbing to the relentless tide of attacks when Mason Mount struck in the 70th minute.

And yet, for all their relief, it took Chelsea just four minutes to squander their lead and two vital points as teenage centre-back Jarrad Branthwaite turned the ball in at the back post.

There was a sense all day that this game could be called off, and Thomas Tuchel might feel more need now to argue with the Premier League’s curious definition of a Covid outbreak, considering almost his entire forward line – Romelu Lukaku, Timo Werner, Kai Havertz and Callum Hudson-Odoi – are currently in isolation, but that will offer no caveat at the top of the table.

After their near-faultless start, Chelsea are now four points adrift of Manchester City and struggling to break out of a laborious rhythm where they dominate at will but are bereft of their usual cutting-edge.

And while they were still able to call on Christian Pulisic as a false nine, an injury-stricken Everton had been stripped back to their bare bones, unable even to fill the eighth place on their bench while 20-year-old Ellis Simms made his debut up front.

Chelsea did dazzle in intervals, with Hakim Ziyech’s brilliant dummy clearing the path for Pulisic’s backheel, but the prevailing pattern was one of wastefulness.

Mount dragged one chance wide and then contrived to shoot straight at Jordan Pickford from point-blank range when a certain goal beckoned.

Everton might have been toothless in attack, but they were admirably dogged. Eventually, though, something had to give.

Shortly after the break, Mount’s shot took a wicked deflection and was tipped over before Ruben Loftus-Cheek spurned a free header from the resulting corner.

Finally, on the stroke of 70 minutes the dam broke. Everton over-committed on a rare attack and were cut to shreds on the counter, with James playing Mount in through Branthwaite’s channel and this time there was no mistake as the England international scored his fourth league goal in successive games.

But for all their struggle, irritation, huffing and puffing, it took just four minutes for Everton to strike back. Anthony Gordon’s free-kick swerved across the face of goal, evading almost everyone in its path, before Branthwaite stretched a leg and turned the ball in at the back post.

The dying stages were a fitting description for the Chelsea onslaught that followed.

Pickford made a spectacular save low to his right to tip away Thiago Silva’s bulleted header, crosses were scrambled away and Chelsea’s frantic efforts were made to no avail.

Everton refused to buckle, and Chelsea were left to rue a pain they’ve started to know all too well.