In a match devoid of any real defending presence, the Gunners made the most of their opponents' errors to notch up their first away win in the Premier League in nine attempts after being down twice in the match.
Robin van Persie's hat-trick proved the difference in the end as the Arsenal captain took his season tally to ten in ten appearances (28 goals in his last 27 league games) with nine of those coming in his last five matches as Chelsea suffered their second derby defeat in two weeks which was only their second derby loss at Stamford Bridge in the past 33 at the venue.
Chelsea took the lead in the 14th minute when Frank Lampard ghosted into the centre of the area behind Per Mertesacker to meet Juan Mata's cross from the right after he beat Andre Santos and the England veteran put away his header with consummate ease for his first goal at Stamford Bridge against Arsenal.
Just over 20 minutes later, Aaron Ramsey unlocked the Blues defence with a pinpoint pass to Gervinho who was on-side and with two choices, he chose to slide into the path of van Persie who finished with ease to make it 1-1.
On the stroke of half-time, Chelsea again took the lead when Lampard's corner was met by John Terry's side-footed attempt from the six-yard box which came courtesy of Mertesacker's poor defensive effort. The German was again beaten to the ball, this time to concede a very soft goal as the Blues celebrated with vigour.
Four minutes into the second half, Arsenal leveled when Alex Song found a barnstorming Santos inside the area and the Brazilian finished neatly past Petr Cech for his first league goal for the club, six minutes before the Gunners hit the front when Theo Walcott slipped over on his way towards goal but somehow managed to pick himself up and wriggle free just outside the area before whipping his shot past Cech at the near post for 3-2.
Just to add a further twist to proceedings, Chelsea were able to level at 3-3 with 10 minutes remaining when Mata got free outside the area and despite being under extreme pressure from Song, got his shot off which swerved away from Wojciech Szczesny and into the bottom left corner, sparking the Stamford Bridge crowd.
However, with five minutes left, van Persie saved the day for his side when he pounced on a boor backpass from Florent Malouda towards Terry, taking possession and advancing into the area before rounding Cech and slotting home for a 4-3 lead.
He then finished off the contest with an absolute peach in injury time when the Gunners pushed forward on the counter-attack with the ball ending at the feet of the Dutchman who hit a brilliant swerving shot past Cech to help send the North Londoners to sixth on the table and inflict Chelsea's first home defeat of the season.
It could have been more for both sides with Arsenal missing two gilt-edged chances early when Walcott got in crosses from the right, first for Gervinho who missed from pointblank range before van Persie put his side-footer over the crossbar, whilst Chelsea saw an opportunity spurned on the half-hour mark when Daniel Sturridge skewed his one-on-one with Szczesny wide before he was called off-side when he had the ball in the back of the net just before half-time.
Another talking point of the game was the yellow card shown to Szczesny in the 50th minute. The Arsenal keeper got the benefit of the doubt from referee Andre Marriner when he came flying out of the area and made contact with Ashley Cole but luckily for the Gunners he was not sent off as another poor defensive moment almost cost the visitors with the Polish gloveman keeping out Lampard's ensuing free-kick.
Nonetheless, Arsenal stood tall in the end and managed to record a victory which could really kickstart their campaign after a spluttering start although their defence, and Chelsea's, will have to improve markedly if they want to mix it with the likes of Manchester City and Manchester United.
TRIBAL ASKS:Robin van Persie is on fire. Is he is the most in-form striker in the world at the moment? Also, did both sides fail to show any defensive respect to their opponents?