Robin van Persie's hat-trick inspired Arsenal to an incredible victory against Chelsea as their recovery gathered momentum in a Stamford Bridge thriller.
The Gunners captain demonstrated his importance to the team by taking his tally to an outstanding 28 goals in 27 Premier League games as Chelsea slumped again after their shock defeat at QPR last week.
And it was a miserable afternoon for Chelsea and England captain John Terry at the end of a week in which has he faced allegations of racial abuse against QPR's Anton Ferdinand - claims he vehemently denies.
Terry scored to give Chelsea the lead just before half-time but then slipped crucially late on to gift Van Persie a goal and a lead Arsenal never relinquished.
Frank Lampard had headed Chelsea in front after 14 minutes but, in a game strewn with defensive errors, Van Persie put Arsenal back in contention from Gervinho's pass.
Terry's goal looked to have put Chelsea in control on the stroke of half-time but Arsenal's response presented a compelling case for Arsene Wenger's insistence that reports of his side's demise have been greatly exaggerated.
Andre Santos equalised and the outstanding Theo Walcott put Arsenal ahead for the first time before Juan Mata's spectacular strike set up the finale to an enthralling encounter.
Terry lost his footing to allow Van Persie to race clear for Arsenal's fourth after 85 minutes before the Netherlands striker completed a second treble against Chelsea by hammering his third past Petr Cech deep into stoppage time.
Wenger's wild celebrations with his players and backroom staff told the story - and made it eight wins in Arsenal's last nine games.
Arsenal have been piecing their season back together after a poor start and the manner of this win will provide added reserves of confidence and self-belief.
For Chelsea coach Andre Villas-Boas, this was his most sobering moment in the Premier League and he looked stunned on the sidelines at the regularity with which the home defence was exposed.
Fernando Torres was recalled in place of the suspended Didier Drogba and he was only denied a goal in the opening seconds by Laurent Koscielny's intervention - a moment that set the tone for a game filled with attacking quality and littered with errors.
Walcott, in front of watching England coach Fabio Capello, was Arsenal's catalyst and twice delivered crosses that should have produced goals in the opening stages.
He presented Gervinho with what looked a certain goal only for the striker to fire wide with the goal at his mercy, then found Van Persie unmarked at the far post, but the striker could not keep his effort down.
Arsenal paid the price for that wastefulness when Chelsea took the lead. Mata was afforded too much space by Santos and when the ponderous Per Mertesacker missed his cross Lampard timed his arrival perfectly to head past Wojciech Szczesny.
Lampard was then the creator with a wonderful ball to release Daniel Sturridge, but he scuffed a half-hit shot across the face of goal.
For all their frailty at the back, Arsenal possessed genuine menace in attack and they carved through Chelsea with ease to restore parity nine minutes before half-time. Aaron Ramsey's pass was perfection and Gervinho took the unselfish option to set up Van Persie for a tap-in.
Terry, almost inevitably, made his mark on the game when he put Chelsea back in front seconds before the interval, sending a scrambled finish past Szczesny from Lampard's corner.
If Chelsea hoped this blow would have a detrimental effect on Arsenal, they were to be sorely mistaken as the Gunners surged forward after the restart.
Van Persie's shot was blocked by the legs of Cech and the impressive Ramsey was inches over before Santos suggested his greatest qualities may lie in attack when he beat the Chelsea keeper with some composure to put Arsenal level once more.
Walcott's display deserved a goal and it duly arrived after 55 minutes. As he had done throughout, the winger ran straight at Chelsea's defence, riding two challenges and even falling before firing an emphatic shot past Cech.
Szczesny was then fortunate to escape with a yellow card for hauling down Ashley Cole outside the area - but the drama simply continued until the final whistle.
Mata put Chelsea back on terms with a swerving 25-yard shot, although a furious Wenger was convinced substitute Romelu Lukaku had fouled Santos in the build-up.
As Chelsea's fans sensed a late winner, they were stunned when Terry's slip proved crucial. He fell to the ground as he tried to retrieve a wayward pass from Florent Malouda, leaving Van Persie to show his nerve by rounding Cech to score.
And Van Persie fittingly had the final word with seconds to go by escaping Chelsea's defence once more to thump high past Cech in front of Arsenal's joyous supporters.