Harry Redknapp's CV took a real hit on Sunday as the Gunners produced a sensational comeback to inflict Spurs' biggest derby defeat since 1978.
Tottenham looked certain to enhance Redknapp's England credentials by making him their first manager for 86 years to win away against the Gunners for two successive seasons and first to do the double over them for 19.
But, in a complete reversal of last season's corresponding fixture, the visitors threw away a two-goal lead to concede five at Arsenal for the first time since 1934.
It was an amazing performance by a Gunners side who lost 8-2 at Manchester United at the start of the season and 4-0 at AC Milan 11 days ago, Arsene Wenger's men once again inspired by talismanic captain Robin van Persie.
Arsenal looked all over the place at the back as Spurs raced to a 2-0 lead through Louis Saha and an Emmanuel Adebayor penalty.
But Van Persie refused to accept defeat, helping his side score twice in three minutes to go in level at half-time, netting the equaliser after Bacary Sagna pulled a goal back.
Arsenal - who leapfrog Chelsea back into fourth in the Barclays Premier League - were rampant after the break, Tomas Rosicky completing the comeback and Theo Walcott scoring twice before Scott Parker was sent off to complete Tottenham's misery.
It looked like being so different after four minutes when Arsenal's shambolic defending from Milan resurfaced.
Former Gunners striker Adebayor, 28 today, played the ball into a gaping hole for Saha to run into, with Thomas Vermaelen's lame block only succeeding in deflecting the Frenchman's shot over the stranded Wojciech Szczensy.
The home side fought back, Kieran Gibbs seeing a dubious penalty appeal rejected and Parker getting away with an accidental handball.
It was breathless stuff and Szczensy beat away another Spurs effort before Van Persie wasted a glorious chance to level when he drilled wide after his initial shot was blocked.
He went even closer six minutes later with a drive that deflected into the sidenetting, his resulting corner seeing Brad Friedel acrobatically tip over Rosicky's header.
Arsenal were beginning to dominate but more risible defending almost saw Spurs double their lead on the break, Szczensy denying Adebayor and Kyle Walker sending the 25-yard rebound just over the crossbar.
Parker, who was everywhere, was booked after clattering into Van Persie moments after being denied a free-kick of his own, with Luka Modric also carded for dissent.
Laurent Koscielny immediately followed for upending Niko Kranjcar, Tottenham immediately surging upfield to win a controversial 32nd-minute penalty.
Gareth Bale was under all sorts of pressure from Gibbs but threw himself to the floor under what looked no contact from Szczensy.
Adebayor kept his cool to rub salt into the wound but wisely chose not to celebrate.
It could have been 3-0 before half-time had Bale chosen to pass rather than drill a shot too close to Szczensy and Spurs were made to pay when Arsenal sensationally hit back before half-time.
The first goal came five minutes before the break, Van Persie desperately unlucky to hit the post before Mikel Arteta swept the ball back in and Sagna powered home a header.
Van Persie then sent the Emirates into raptures, pouncing on a loose Benoit Assou-Ekotto clearance, and turning onto his left foot before curling deliciously beyond Friedel.
Redknapp responded by throwing on Rafael van der Vaart and Sandro at half-time for Saha and Kranjcar but Arsenal's tails were up and only another fabulous Friedel save from Yossi Benayoun's precise finish prevented them completing the comeback.
Benayoun then caught Walker with a tackle that forced the full-back off and he was barely back on when Rosicky made it 3-2 in the 51st minute, playing a one-two with Sagna before poking in the latter's deflected cross.
Tottenham finally got a foothold but it was Arsenal who were now dangerous on the break, Walcott drilling inches wide, while Sandro was completely off the pace, rightly booked for tripping Van Persie.
As in the first half, the Gunners scored twice in three minutes to kill the game.
It was a brilliant counter-attack that brought the 65th-minute fourth goal, Benayoun releasing Van Persie, who held off Ledley King and Younes Kaboul before squaring for the onrushing Walcott to clip the ball over Friedel.
It was Tottenham's defence that was now all over the place and Kaboul played Walcott onside, the winger racing onto Alex Song's pass and finding the bottom corner.
"Harry for England", the Arsenal fans chanted ironically before Rosicky almost made it six after a one-two with Walcott and Parker was shown a second yellow for treading on Vermaelen's toe two minutes from time.