The result did not confirm that the days ahead belong to Arsenal, but they have a stake in the future. If Chelsea's display was spasmodic and clumsy, it was, at least in part, because they had no answer to the rhythm of opponents who might now be ready to enter a new phase. After five years without a trophy there should be an ache to succeed.

Arsenal still did not look commanding in defence despite alterations. That was to be of no account as, from the latter stages of the first half, they hit a tempo that made Chelsea ache. While the losers wonder about the years ahead, Arsenal have reached a moment when they must no longer depict themselves as a work in progress.

It is time simply for the club to be a real power. The age profile will usually be in their favour, and while Theo Walcott has seemed to regress at times to the status of impact substitute, he was a force here. His initial purpose would have been to pin down Ashley Cole, but eventually he achieved much more. Arsène Wenger would be happy to see that as the embodiment of the entire Arsenal project.

This, of course, was merely a single match. The win over these opponents did not cancel out three losses already endured at the Emirates to supposedly lesser visitors in the league, but it might encourage an assurance that will limit the number of lapses. Results transform attitudes, and Arsenal had waited a while for this alchemy.

They presented themselves with a 3-0 lead here after opening the scoring on the verge of the interval. A first victory over Chelsea in 25 months was all but inevitable even then, since Carlo Ancelotti, the Chelsea manager, has a team in decline. Their response with a goal was a last spark of pride in a squad that looked burnt out. Even so, Arsenal had still needed to think long and hard about a test they passed well enough to suggest they may still compete hard for the title.

The match weighed heavily on Wenger. Instead of sticking to habit, he had made decisions that saw, for instance, Johan Djourou and Walcott in the starting line-up in preference to Sébastien Squillaci and Andrey Arshavin respectively. Such verdicts did not have an immediate impact, and for a while Arsenal's play was smooth but lacking a contrasting pointedness in the penalty area.

There had nevertheless been a rising tempo and confidence, which was rewarded in the 44th minute. Alex Song began the move. His pass brushed against Cesc Fábregas before Jack Wilshere returned play to Song, who shot low past Petr Cech from an angle on the left. Arsenal had gradually increased the tempo in a thoughtful fashion that suggested memories of meetings with Chelsea had been cleansed from the memory.

Arsenal's last victory over Chelsea had been in November 2008, the month when they also recorded their most recent win against Manchester United. Arsenal's captain, Fábregas, who had been injured and merely came off the substitutes' bench in the defeat two weeks ago at Old Trafford, said Arsenal had been scared that night. The club does not spend at the level of its peers but, at a time when Manchester City alone look bullish in the transfer market, there should still be a possibility of Wenger's team staying to the fore.

In this match, it was to be expected that there would be a spring in Arsenal's step. Fábregas began his first game for the club since 23 November. Chelsea, too, had a particular midfielder who had not been present at kick-off since 28 August. A 32-year-old Frank Lampard, understandably, could not galvanise those around him or present a danger in the goalmouth. He struck some good passes in the first half, yet did not cause panic.

Arsenal, a goal ahead, had the composure of a side that could afford to be calm, particularly since there was, by then, an erratic tone to Chelsea. With 51 minutes gone, Michael Essien's effort to tackle Robin van Persie merely guided the ball to Walcott, and he drew Cech before setting up Fábregas to shoot into the unattended net.

The competence had deteriorated further at the next Arsenal goal, two minutes later. Florent Malouda was dispossessed by Walcott, and when Fábregas returned the ball to him the finish was elementary. By that stage, all that remained of the once formidable Chelsea was the persistence that counted at a Didier Drogba free-kick, with Branislav Ivanovic leaping above Laurent Koscielny to head a goal in the 57th minute.

In its own way, even that moment has its uses for Arsenal as an indication that they can be more efficient in defence. So far as Chelsea were concerned, the visitors had already been much too capable.