Sunderland proved at Stamford Bridge that fortune favours the brave against Chelsea.
Chelsea's air of invincibility is lost
Tony Yeboah. Remember him? He was the Ghanaian striker probably most famous for that stunning volley for Leeds United against Liverpool in 1995, a ricochet off the crossbar and into the back of David James's goal.
Slightly less celebrated are the two strikes Yeboah scored against Chelsea at Stamford Bridge in March 1995. Their significance? Well, they inspired Leeds to a 3-0 victory and, before Sunday's shock 3-0 defeat at home to Sunderland, it was the last time Chelsea had lost a home league game by a three-goal margin to a side outside their "Big Four" fraternity brothers - Manchester United, Arsenal and Liverpool.
The result and the manner of the performance on Sunday was a chastening experience for Chelsea players, management, fans and, in particular, Roman Abramovich, the owner, who witnessed the heaviest home league defeat since he bought the club in 2003.
Abramovich has cut spending this season and the upshot has been that Chelsea have now lost more games at this stage of the season than at any time in the past decade.
It is all a far cry from the days of Jose Mourinho, the Portuguese alchemist who turned Stamford Bridge into a fortress during his trophy-laden reign; they did not lose a home league game during his three years in charge.
It would be too early to start calling Stamford Bridge a bouncy castle instead of a citadel following one home defeat, but Sunderland could well have removed the air of invincibility Chelsea possessed at home.
Most of the fall out from Sunday's game has centred on Chelsea's shortcomings. But, in rewriting the record books, Sunderland should be praised for their approach.
Steve Bruce's reward for playing two forwards brought his first top-flight victory in London in 24 attempts as a club manager.
Nedum Onuoha's goal ensured that Sunderland became the first team to score at Stamford Bridge in 915 minutes, and their resolute defensive display meant Chelsea failed to win a home league match for the first time since November 2008.
Chelsea, you suspect, would have also been peeved that two of the goals they conceded were scored by players on loan from two of their title rivals - Danny Welbeck, from United and Onuoha, from Manchester City.