Mauricio Pochettino watched from the directors' box as calamitous Chelsea defending killed any momentum earned before the international break.
A barely believable 90 seconds saw Newcastle score two goals as Marc Cucurella and Benoit Badiashile failed to mark Jamaal Lascelles before Thiago Silva's poor touch allowed Joelinton to kill the game.
Chelsea then lost their heads with Reece James getting sent off for a poor challenge to earn a second yellow card. Anthony Gordon scored against the 10-man Blues to pile on the misery.
The defeat was feeble, considering Newcastle were without a whopping 13 players after the international break. Raheem Sterling had cancelled out Alexander Isak's opener before the break, but that turned out to count for nothing.
No fight, no composure
In fairness, Chelsea fought hard for 60 minutes but as soon as Lascelles' header went in, it was game over.
A dreadful reaction from the Blues followed. Having been in the game before, it was a total collapse.
Chelsea couldn't close anyone down, maintain possession or compete. The lack of competitive spirit in this group is an issue Pochettino has identified after other defeats this season, but this loss was particularly poor.
Ill-discipline
James' red card summed up another character flaw in this group: they can't handle setbacks.
The captain pulling back Gordon, as he did, was so poor and cost his side dearly.
He will now miss Brighton's visit to Stamford Bridge next weekend, as will Marc Cucurella after his yellow card. Three other Chelsea players were booked in the implosion.
Raheem Sterling stunned
After the match, Sterling sat on the bench, alone, with a blank stare. The highly decorated winger was the only good performer on the night.
The 28-year-old scored a stunning free-kick but delivered so much more than just that strike for his team.
His excellent counter-attacking ability allowed Chelsea to drive up the pitch as he provided a constant threat on the break. He created Nicolas Jackson's only chance of the match, and his energetic pressing forced mistakes.
Newcastle supporters booing his every touch was almost a sign of respect, given they knew exactly the threat he carried.
Even the in-form Cole Palmer wasn't at his best, with Sterling the only resistance to Newcastle on Saturday. No wonder he looked at a loss for words after the match and wanted to be alone.
