The Gunners went to Stamford Bridge as underdogs, but they shocked their London rivals with a stunning display of attacking football in a 5-3 win. Arsenal are now just seven points behind second-placed Manchester United - a feat that seemed impossible when United put the Gunners to the sword with a merciless 8-2 thrashing three weeks into the campaign. With Arsenal having lost to rivals Liverpool, Tottenham and United, Wenger admits his team would have been doubting whether they were good enough to compete with their top-four rivals before last weekend's trip to Stamford Bridge. But, having overcome Chelsea, he thinks his team will now go into any match against major opposition thinking they can win. "For us it was a massive test, first quality-wise and second to see if we could compete in terms of quality with top teams," Wenger said. "Nobody knew (whether we could) before the game. It was also a test to see if we were capable of winning when playing well, and we did. "It was the team's first big win together and before the game in their heads there was uncertainty about whether they could win a big game. "It was a very exciting game with goals. It was an enjoyable weekend." The excitement among the Arsenal squad was clear at the final whistle when they celebrated in raucous fashion in front of their travelling fans at Stamford Bridge. Although Wenger was pleased to see the euphoria on the faces of his new-look squad, he has warned that the Gunners are still a long way from becoming a title-challenging side again. "At the time, you want them to be as happy. There is a need for us to communicate with our fans again and that was a good chance, we wanted that," said Wenger about the celebrations. "After that (match), we have won nothing. We must just use it as a springboard to go further towards our target. The players know that." Despite the pulsating nature of the derby, the way that Arsenal conceded their three goals was a big concern for Wenger. Slack marking on Frank Lampard and John Terry allowed both players to convert from close range on Saturday and Juan Mata was given space to thunder a glorious 25-yard effort past Wojciech Szczesny late on to make it 3-3 before Robin van Persie scored a brace to seal the win for Arsenal. The return of Thomas Vermaelen from injury, and the continued improvement of Laurent Koscielny and Per Mertesacker should give Wenger cause for optimism, but he admits watching his team defend on Saturday was "torturous" at times. "Is it torturous to watch us play how we do sometimes? Yes," Wenger said. "We gave them too much room, too far in midfield, exposed on long balls over the top, so you can only hope you do not pay too much for it. "There is still some room for improvement defensively. "In the first half we were too vulnerable. Chelsea missed some chances, so we can still improve." Wenger's team could take a big step towards qualification to the knockout stages of the Champions League on Tuesday night if they beat Group F rivals Marseille at the Emirates Stadium. The Arsenal boss admits it is important to put the joyous memory of the Chelsea win to bed if they are to secure their qualification, which will be all but guaranteed if the Gunners win and Olympiacos fail to beat Borussia Dortmund in Germany. He said: "We want just to qualify. Our job is to forget about the last game, take the positives out of it, and focus on the next one just as we had to do when we lost 8-2 to Manchester United."
