At the end, they celebrated in warrior style, shirts off and thrown to the crowd, chests out, muscles rippling, straining against the material of sweat-soaked undergarments. We have seen this emotion from Chelsea before, marking big victories in the battlefields of the north; but this was Arsenal, delivering against the odds once again this season and relishing the moment, extracting every last drop of adrenalin from it.

Arsène Wenger, the Arsenal manager, said to win at Stamford Bridge showed the character of his team, and he meant it as a positive. Yet, equally, it could be argued that players capable of beating Manchester United and Chelsea this season but unable to get the better of Stoke City, Aston Villa and Manchester City are showing character of a more worrying sort: that of the big-time Charlie. Wenger, at all times a thinking man, had an answer for that, too. “Sometimes part of the learning process is to find out how to win when you are not on the edge,” he said. “We were there today and, in other matches, it will not be the same. I have an intelligent group, though, and they must learn how to win every type of game. Just to turn up is not good enough.”

Arsenal turned up yesterday, though, certainly after half-time. Not necessarily in the style expected of them, all dash and panache, passing Chelsea off the pitch, but in the manner of one of those admirable, battling teams who get an advantage, not entirely on merit, and defend it. This was an Arsenal seldom seen, eye-catching players doing grimly determined jobs. Samir Nasri, wide on the left, barely featured in an attacking move, but he boxed José Bosingwa in the right-back position, when his wing game has been such a feature of Chelsea’s forward play this season.

Arsenal’s back line was magnificent, save for Johan Djourou’s own goal after 29 minutes, with William Gallas the star. His reception at Stamford Bridge was as hostile as could be expected, yet he rose above it to deliver — irony of ironies — the captain’s performance that was so often missing when he wore the armband. His celebrations were particularly passionate at the end. Only time will tell if this was too little, or too late.

The result propelled Arsenal back to fourth place, but they are not re-established as title contenders yet, trailing Chelsea by seven points. The club should prepare for a few sackloads of fan mail from Merseyside, however, for what Arsenal most certainly are this season are Liverpool’s allies. Their past five league results have been of perfect benefit to Rafael Benítez and his players, with wins against Liverpool’s title rivals, Chelsea and United, and three soft defeats neatly undermining their own cause.

Luiz Felipe Scolari, the Chelsea manager, blamed the officials for the defeat and hoped for an apology this morning, but if Mike Dean, the referee, and his assistants do express regret, they should add that they are also sorry that Chelsea had only one shot at goal all match, did not create a chance after Arsenal’s first goal, had their best striker in the stands because of his own foolishness and have only one way of playing, which the rest of the Premier League would appear to have worked out. This result went far deeper than a shout for offside when Robin van Persie equalised, and it did Scolari scant credit that he was prepared to join the ranks of the disgruntled now that his luck has changed.

Yes, Van Persie did look offside when he scored his first goal after 58 minutes, but there were another 36 minutes, including stoppage time, left to play when this occurred and Chelsea’s failure to create a single scoring opportunity in that period is not the fault of the officials. Chelsea lost yesterday because they lacked imagination and were little threat to Manuel Almunia in Arsenal’s goal. They lost because Deco has gone completely off the boil, Michael Ballack is feeling his way back after injury, and Frank Lampard cannot do it all on his own. They lost because, without Ricardo Carvalho, they are defensively vulnerable. They lost because Scolari is in desperate need of plan B. They lost because, with Didier Drogba suspended, there was no impact to be made from the bench. They lost because Van Persie and his striking partner, Emmanuel Adebayor, presented more of a challenge than Nicolas Anelka and Salomon Kalou and, now they are reunited, perhaps Arsenal will, too.

Arsenal are not out of these woods yet and when chaos crowded in on what should have been a simple transition from defence to attack in the first half, it appeared the downward spiral was to continue. Almunia collected a corner from Lampard, but threw the ball wildly, turning what should have been an Arsenal counter into more Chelsea pressure. Bosingwa collected the loose ball, fed Anelka, made a good run for the return pass and his cross was turned into Arsenal’s net by the hapless Djourou, stretching at the near post.

So Chelsea did get the odd good break, and had Lampard not snatched at a chance set up by Anelka in the 51st minute, shooting wide, it might have been different. Instead, Chelsea paid for failing to impose their game and, with such a slim margin between the teams, were exposed by a combination of an assistant referee’s inert flag and Arsenal’s highly ert* Dutchman, Van Persie, who struck twice in three minutes to win the game.

Adebayor won a header against Branislav Ivanovic, who looks no replacement for Alex, let alone Carvalho, and Denilson fed the ball through to Van Persie, who made the most of an assistant referee’s error to finish smartly past Petr Cech. From Arsenal’s next attack, a free kick by Cesc Fàbregas, Adebayor rose above John Obi Mikel and Van Persie lost Lampard to strike an excellent shot on the turn. In recent weeks, Chelsea have looked susceptible to aerial attack, a poor show considering the size of the team.

Arsenal must hope normal service is not resumed against Wigan Athletic at home on Saturday, while Chelsea can only ask for a favour from their old boys, Gianfranco Zola and Steve Clarke, who take their West Ham United team to Anfield to face Liverpool this evening. Much like waiting on that apology from Dean, Scolari would not be advised to hold his breath.

* Yes, I know, but there should be.

Chelsea (4-1-3-1-1): P Cech 7 - J Bosingwa 6, B Ivanovic 5, J Terry 6, A Cole 6 - J O Mikel 5 - M Ballack 6, F Lampard 6, Deco 4 - S Kalou 6 - N Anelka 5. Substitutes: F Malouda 4 (for Mikel, 69min), M Stoch (for Deco, 80). Not used: Hilário, W Bridge, P Ferreira, Mineiro, Alex. Next: Bolton (a).

Arsenal (4-4-1-1): M Almunia 6 - B Sagna 7, W Gallas 8, J Djourou 6, G Clichy 7 - Denilson 6, F Fàbregas 7, A Song 6, S Nasri 6 - R van Persie 8 - E Adebayor 7. Substitute: N Bendtner (for Adebayor, 86). Not used: L Fabianski, C Vela, A Ramsey, M Silvestre, J Wilshere, K Gibbs. Next: Wigan (h).

Referee: M Dean Attendance: 41,760