Sunday's London derby result proved an absolute shocker for both Chelsea and Spurs fans. For the Stamford Bridge faithful, it was a tragedy, but for the north London support, it was nothing short of ecstasy.
Surely, the most confident Tottenham fan didn't leave home for Stamford Bridge expecting to return this jubilant. After all, the Wembley side hadn't won an away game at Chelsea's home stadium in the Premier League era.
They had to look back to Gary Lineker's winner in 1990 as the last time their side won at the Bridge. Younger fans had no idea what a Stamford Bride win felt like. And with Harry Kane out of the starting lineup, expectations couldn't have been that high.
They must have felt an all-too-familiar feeling when Alvaro Morata headed in the opener in the first half. But Christian Eriksen's worldie put them back in it before the end of the period, with a Dele Alli double claiming a first win for Tottenham at Stamford Bridge in 28 long years and sending them home boasting an incredible 3-1 upset.
Even in their lowest of lows, Chelsea had been able to protect home turf against their London counterparts, but all things come to an end at some point. And this one in particular just had to under Antonio Conte.
The Blues boss, who took over in the summer of 2016, seemed set to usher in an era of dominance at Chelsea after storming his way to the Premier League title last season. The Italian propelled the Blues to victory with remarkable tactics, amazing enthusiasm and a bit of charm.
And perhaps that was his downfall.
After winning one of the most difficult trophies there is to win with a squad hardly given a shot, Conte must have looked like a miracle worker to his employers, who probably believed they could keep things rolling with minimal spending as long as Antonio was in charge.
The first half of the season, though, must have been warning enough. Yet the Blues paid little heed, seemingly expecting their manager to at least clinch a top-four spot and remain afloat in the Champions League.
There's little hope of that now, with Tottenham having widened the gap between fourth and fifth to eight points. There's also very little hope of Conte staying, as Roman Abramovich is (most likely) already studying managerial options, while the frustrated coach is likely to walk away on his own volition even if he isn't relieved of his duties.
There really was a great opportunity to build on last season's success, but Chelsea seem quite satisfied to win a title every three or four years, which admittedly isn't at all bad. But why go for not bad when it's possible to attain greatness?
They're now staring at another season sans Champions League football, which certainly isn't a good look for a top club, and only have themselves to blame.
Conte isn't totally in the clear here, however. He would have probably been much better off had he not exiled Diego Costa last year. And his tactics have been questionable at times. But Chelsea should shoulder most of the blame as they're probably about to lose a great coach and set themselves back a few years... again.