Leaders turn on the style as Arsenal rue missed chances

Arsenal 1 Chelsea 2: Goals from Fernando Torres and Juan Mata see unbeaten Chelsea capitalise on Arsenal's defensive frailties from set-pieces to inflict a first defeat of the season for Arsène Wenger's side

A fixture invariably flush with goals and incident provided both, plus a significant result: by inflicting a first defeat of the season on Arsenal, Chelsea preserved their unbeaten record and League leadership. The outcome of an exciting derby may have been determined by two set-piece goals – both following free-kicks taken by Juan Mata – but it was essentially a just one, rich reward for the way the west London side matched the north Londoners' football and proved more solid defensively to move seven points above them in the table.

For the second Saturday running they left out Frank Lampard, who did not qualify for even a few minutes' appearance money, and this time the use of three creative players strung across midfield just behind Fernando Torres worked far better than in the fortunate victory at home to Stoke City. Eden Hazard was more disciplined on the left than a week earlier and, when he did move across, linked up cleverly with Mata and the mercurial young Brazilian Oscar.

Thus far, then, Roberto Di Matteo is bringing off the enviable trick demanded by Chelsea's owner Roman Abramovich of not only winning but doing so in style. "I'm very pleased with the performance," he said. "We came here to take the initiative and I think we won deservedly. It gives the players confidence and belief that we can play differently. We've had a good start and hopefully we can build on that, but we know how much work there still is to do in integrating the new players."

They are currently achieving that a little better than Arsenal, who have a gem in Santi Cazorla as their own playmaker, but cannot be entirely sure of the best way to build around him. Neither Olivier Giroud, who again missed a late chance, or Lukas Podolski have been convincing; Arsène Wenger, a little stubbornly, continues to pick Aaron Ramsey on the right instead of Theo Walcott, although he is not a natural wide player.

Now he has lost Abou Diaby for another three weeks with a thigh strain. The Frenchman hobbled off after fewer than 20 minutes, which did at least allow Ramsey to revert to his proper position; Alex Oxlade-Chamberlain, rather than Walcott, came on, the latter having to wait until the last quarter of the game to appear along with Giroud.

Wenger's two complaints were that Chelsea had few real chances and that his defence dealt badly with those that did materialise. He might also have blamed the concession of unnecessary free-kicks in the final third, a fault that his returning captain, Thomas Vermaelen, was prone to. That was how the first goal came about in the 20th minute. Mata swung the free-kick into a dangerous area where David Luiz had been left unmarked and although the ball passed beyond him, Torres won his penalty-area wrestling match with Laurent Koscielny, leaving the Arsenal defender facing the wrong way as he hooked in a clever shot for his fifth goal of the season.

Torres should have added another two minutes later but was left vainly claiming a penalty instead. He brushed Koscielny aside, outpaced him and veered round the goalkeeper, Vito Mannone, before producing an air-shot. His claims to have been fouled by a retreating Koscielny had no substance. Gervinho's goal just before the interval ought, therefore, to have merely been offering Arsenal a little hope, but turned out to be an equaliser.

Oxlade-Chamberlain made it, staying calm on the right to pick out Gervinho, whose fine turn and finish brought his fourth goal of the campaign; as many as in the whole of last season. So Arsenal and their supporters finished the half on a high, only to be cast down again within 10 minutes of the restart. Once more Vermaelen gave away a free-kick, earning one of the afternoon's five yellow cards in the process. Mata lined it up some 30 yards out and this time kept the ball lower, tempting Koscielny into a lunge and a slight touch that left his goalkeeper on the wrong foot.

From then on Arsenal pressed and Chelsea countered swiftly and dangerously. "To come back in every game is difficult," Wenger lamented. "It's impossible because you have all the risk and they can hit you on the counter-attack." They did just that, although only in between some fine goalkeeping.

Petr Cech made two excellent saves, firstly as Podolski headed a cross by Kieran Gibbs, and then as Giroud's shot took a slight deflection. The expensive French striker, who has yet to find his feet in London, could have made himself a local hero in added time; sent through by Oxlade-Chamberlain, he seemed to have eluded Cech but could only hit the side-netting rather than the jackpot.

Arsenal (4-2-3-1): Mannone; Jenkinson, Koscielny, Vermaelen,Gibbs; Arteta, Diaby (Oxlade-Chamberlain, 17); Ramsey (Walcott, 66), Cazorla, Podolski (Giroud, 66); Gervinho.

Chelsea (4-2-3-1): Cech; Ivanovic, Terry, Luiz (Cahill, 81), Cole; Ramires, Mikel; Mata (Bertrand, 84), Oscar (Moses, 73), Hazard; Torres.

Referee: Martin Atkinson

Man of the match: Hazard (Chelsea)

Match rating: 8/10