Sunderland handed champions Chelsea a footballing lesson as they chalked up their first away win of the season in stunning style.
The red-hot Black Cats simply blew Carlo Ancelotti's table-toppers away with a searing display which will surely rank as the finest of Steve Bruce's reign so far.
Sunderland bossed this contest for almost the entire 90 minutes and Chelsea never looked like coming back after Nedum Onuoha slotted home a sublime opener just before half-time.
Another goal from the in-form Asamoah Gyan added some insurance just after the break as Sunderland systematically dismantled their illustrious hosts.
And a late goal from the superb Danny Welbeck added further lustre to a result which will reverberate around the league.
Chelsea hadn't conceded a home goal this season - winning all six of their previous fixtures on home turf and scoring 17 times - but they just couldn't live with a Sunderland side who set up in a 4-4-2 formation and went for the jugular.
Pre-match, boss Bruce pledged to have a go at the champions and that certainly proved to be the case as the visitors roared out of the traps.
Indeed they could have taken the lead inside three minutes had Onuoha got a better contact on the ball in front of Petr Cech after Michael Turner headed Bolo Zenden's free kick back across the box.
Gyan also curled a shot over the top from distance as Sunderland made the early running.
The champions, however, came close 17 minutes in as John Mikel Obi sent Nicolas Anelka racing clear only for Gordon to bravely dive at his feet and turn the ball away from danger.
Then, just moments later, Yury Zhirkov's nifty footwork took him between two defenders but he dragged his shot well wide of the far post from 10 yards out.
The hosts built some momentum briefly as defender Branislav Ivanovic headed over from a corner before summer signing Ramires gave Craig Gordon his first real test of his maiden visit to Stamford Bridge.
Didier Drogba's corner was headed out by Turner as far as the Brazilian, who responded with a header of his own which was looping into the top corner until Gordon grabbed the ball at the last moment.
Drogba twice came close with powerful free kicks on and then just after the half-hour, but Sunderland stood firm.
Their pre-match pledge to attack was certainly bearing fruit as home keeper Cech single-handedly prevented his side from going behind just after the half-hour.
Cech pulled off a fantastic save to deny Welbeck, whose header from an Onuoha cross looked set to sneak into the corner until the big stopper somehow got across to claw the ball away for a corner.
The Czech international was somewhat relieved to see Kieran Richardson's shot fly wide through a crowd of bodies before pulling off another fine stop just moments later.
Gyan produced a clever through ball to play in the excellent Welbeck, who saw his low shot turned away.
Now the visitors' tails were truly up. Ivanovic was close to receiving a red card when he pulled down Welbeck, but referee Chris Foy opted to show just a yellow.
Cech was forced into two more good saves as the onslaught continued - turning away a Gyan shot and then getting across his goal to save with his legs when Richardson prodded the rebound goalwards.
But Chelsea's luck ran out just before the break as Sunderland ended their clean sheet record at nine successive home games.
When the richly deserved goal came, it did so in style. Jordan Henderson's ball into the box was headed away as far as Onuoha, who probably couldn't even have imagined what was to come.
Looking up and seeing no options, he set off towards goal, slaloming past two challenges, powering beyond a third and sliding a low shot past Cech and into the corner of the net.
What a way for the on-loan Manchester City defender to score his first goal for Sunderland and only the sixth of his career.
With their previously blemish-free defence breached, Chelsea went in at the break stunned and the visitors came out hungry again in the second period.
And they didn't take long to cash in on their superiority, doubling their advantage with another goal of the highest quality seven minutes after the restart.
The dangerous Welbeck did the spadework under pressure and fed Henderson, whose incisive through ball sent Gyan racing in behind a flat-footed Chelsea defence.
Clean through, Gyan kept his already notorious cool, rolling an angled shot past a helpless Cech and into the net for his sixth goal of the season.
It was an excellent strike from the Ghanaian, who seems to be really getting his teeth into life with the Black Cats.
Chelsea needed a response - Drogba shot weakly at Gordon - but with Ancelotti's men rocking Sunderland almost extended their lead.
Former Blues man Zenden touched a Gyan cross straight at Cech, and Welbeck was unlucky to see a whipped cross-shot fly through a crowd of bodies and just past the far post with the keeper well beaten.
But try as they might, Chelsea just couldn't respond and two errant efforts from Anelka were as close as they got.
Meanwhile Onuoha showed more silky skills in the box and saw his shot deflected behind, while Richardson's long-range blast flew well wide.
And it was left to Welbeck to wrap up an incredible afternoon three minutes from time.
Chasing a long ball down the right channel, Richardson's pace put Cole under pressure as the Chelsea man tried to run the ball out of play.
Cole attempted to find keeper Cech, but the backpass was woeful and Welbeck was left to tap the ball into an empty net for an easy - and well deserved - goal.
That was the signal for Stamford Bridge to empty as the Chelsea fans trickled away having seen their side given a complete footballing lesson.