Manager Arsene Wenger maintains his bruised Arsenal squad cannot afford to feel sorry for themselves if they are to bounce back from a nightmare opening day defeat by Aston Villa and keep alive their Champions League dream in Turkey next week.

The Gunners were booed off after they lost 3-1 at home to an industrious Villa side, who were helped somewhat by a controversial second-half penalty which was swiftly followed by the dismissal of defender Laurent Koscielny for a second yellow card.

Given the criticism for failing to land any major summer transfer targets despite having millions in the bank, it was hardly the ideal warm-up ahead of Tuesday night’s first leg of a crucial Champions League play-off against Fenerbahce at the intimidating Sukru Saracoglu stadium, where Arsenal could well be without defenders Kieran Gibbs and Bacary Sagna as well as England midfielder Alex Oxlade-Chamberlain, who all went off yesterday.

Wenger, though, challenged his players to show their strength of character and produce the required response in Istanbul.

“The next game becomes very important when you come out of a game like that,” the Arsenal manager said. “You must not let the disappointment gain in the spirit of the players

“The resolute attitude we had against Villa we have to keep and bounce back on Wednesday, that is what it is about.”

Midfielder Jack Wilshere accepts there can be no dwelling on the disappointment of yesterday's capitulation if Arsenal are to stay on course for the lucrative group stages of the Champions League.

“We are not happy, we have got to look at ourselves,” the England international said.

“We have got a big qualifier coming up and there can be no mistakes now, we have got to push on.

“We have got to pick ourselves up. We need to put in better performances and win games.”

There was little sign of what was to come when Arsenal raced into the lead on six minutes as Olivier Giroud swept home a left-wing cross from Oxlade-Chamberlain, who was replaced at half-time with what could prove to be a serious knee injury.

However, Villa, who battled against relegation last season, responded well and were level after Gabriel Agbonlahor had been upended by Wojciech Szczesny. Although the Poland goalkeeper saved Christian Benteke's penalty, the Belgian headed in the rebound.

After both sides produced plenty of hefty challenges, the defining moment of the match came on the hour.

Koscielny looked to have won the ball in his sliding challenge with Agbonlahor, only for referee Anthony Taylor to belatedly point to the penalty spot once again.

Benteke only needed one attempt this time as he put Villa in front before Arsenal’s afternoon got worse as Koscielny, booked for his foul on Agbonlahor, was shown a red card after collecting a second caution when he went through the back of Andreas Weimann.

Although Wenger admitted the "stubborn" performance of Taylor had left him "quite amazed", Arsenal still created enough chances with 10 men to get something from the game as Villa goalkeeper Brad Guzan made two exceptional saves to deny first Tomas Rosicky and then Santi Cazorla.

Villa defender Antonio Luna, signed from Seville, added a late third for the visitors on the break before chants of "spend some money" and jeers rang out from the disgruntled home support.

United States international Guzan felt the victory was testament to the spirit within the Villa squad, forged during last season’s battle for survival.

“We are confident in what we are about as a team, in our abilities,” he said.

“We wanted to come down here and make a statement.”

Villa head to Chelsea for a rearranged match on Wednesday night.

Guzan added: “To come down here and get a result like we did, we can take this result forwards.

“We know there is a lot of football to be played in a long season ahead of us, so we will enjoy this now, then be focused and ready to go again at Chelsea.”

Yesterday’s match also featured the first use of the Premier League’s new goal decision system (GDS) when a 52nd-minute effort from Villa midfielder Fabian Delph struck the inside of the right-hand post and rolled along the line.