Tottenham had been convinced this was their opportunity to be crowned kings of north London, a position they have not held for any length of time since finishing five places ahead of Arsenal in 1995. And for 45 minutes, all things seemed possible, including a first Spurs win in the fixture for six years. But once last week's fall guy Robert Pires came on at half-time the game was transformed.
Pires it was who struck the deserved equaliser to Ledley King's header as his team dominated the second half almost as comprehensively as the home side had done the first. Little wonder that as he trotted down the tunnel after the final whistle, the Frenchman sported a grin as wide as the traditional gap between these clubs over the past decade.
But if Pires could enjoy his 32nd birthday celebrations all the more last night, and Arsenal supporters could hold their heads up in the hostelries of north London, any tendency to believe the old order has been effectively upheld should be balanced against the evidence of the first half here.
Like last season's FA Cup final and other more recent occasions, the absence of Thierry Henry - who may return against Sparta Prague in midweek - left Arsenal looking like a team in search of a forward line; the midfield lacked a leader, and at the back Kolo Touré found Mido's physical presence a handful and Sol Campbell for once appeared affected by nerves on the ground where he is regarded as Judas Iscariot in disguise.
The upshot was that even without the suspended Edgar Davids alongside him, Michael Carrick was able to control proceedings just in front of King and Michael Dawson; an impressive English trio to set before Sven Goran Eriksson.
Indeed, Spurs started with no fewer than seven Englishmen and while it is simplistic to suggest that foreign players do not understand the nature of local derbies - which do, after all, take place all over the world - the irresistible feeling yesterday was that Tottenham were "up" for the game in a manner their local rivals could not match.
Arsenal's two early bookings, for fouls by Gilberto Silva and Mathieu Flamini, were a sign of desperation under pressure rather than the sort of commitment being shown by every man in a white shirt. In a couple of instances the shrieking home crowd were annoyed that Steve Bennett penalised Arsenal instead of allowing play to continue, but the second time that happened, a goal resulted.
Flamini fouled Aaron Lennon on the right and then made things worse by allowing King to slip away from him and head in Carrick's out-swinging free-kick.
Although Dennis Bergkamp played quite far forward in support of the ineffective Jose Antonio Reyes, there was little for either of them to feed off at that stage. "You can't see who's going to score for them," Chris Waddle told Radio Five Live listeners.
Freddie Ljungberg looked the one possibility, stealing into space down the middle, but he and then Francesc Fabregas were too slow to take advantage of the half-chances which fell to them.
Eyes were more often drawn to the other end of the pitch, where Jermaine Jenas fed Carrick for a fizzing left-footed drive just past the post and then hit an equally fierce shot from a similar spot that Jens Lehmann did well to touch over the crossbar - all the more so as there had been a slight deflection off Campbell.
It was typical of Spurs' spirit that Teemu Tainio should refuse to come off despite having to change his blood-soaked shirt and shorts after a collision with Campbell that he clearly felt involved an elbow. "There was no intention or malice," the Arsenal man insisted, which did not prevent an angry verbal exchange with a spectator at full-time.
The first substitution of the match was therefore Pires's entrance for the second half at the expense of Flamini. Just as crucially as offering a new threat down the flanks, the change allowed Fabregas to move into his favoured position in the centre, from where he and Gilberto set the pace and tone of a contrasting 45 minutes.
There was still an opportunity for Jermain Defoe, wriggling in to hit Lehmann's legs, before Arsenal took control. Pires floated a free-kick wide and twice set up the second substitute, Robin van Persie, bringing one stunning left-handed save from Paul Robinson.
By the 77th minute, an equaliser was looking like a matter of time. It materialised, like Tottenham's goal, from a free-kick, after Reyes went down on the left. Robinson may or may not have found the sun as much of a hazard as Bergkamp's swirling cross - which is surely why goalkeepers are allowed to wear caps. His unconvincing punch fell perfectly for an unmarked Pires to drive in his eighth goal in 10 games against Spurs and set off on a celebratory run all the way back to Lehmann.
The birthday boy may even have shared some uncomplimentary words about Tottenham with the goalkeeper, who had earlier been hit by a conker, of all things, thrown from the crowd.
Spurs were unable to land another blow on him before the finish.