Goals from Kieran Gibbs, Aaron Ramsey and Olivier Giroud have put Arsene Wenger's men in a commanding position in the Champions League play-off ahead of next week's second leg
Second-half goals from Kieran Gibbs, Aaron Ramsey and a penalty from Olivier Giroud made sure of the win, with the Gunners now firmly in the driving seat ahead of next week's second leg at the Emirates Stadium.
Arsene Wenger was forced into one change from the opening day of the Premier League season with injury to Alex Oxlade-Chamberlain ruling him out of the trip to Turkey.
Santi Cazorla replaced the England international with Lukas Podolski having to settle for a place on the bench.
|By Jamie Dunn
The season could not have started much worse for Arsenal, but Saturday's defeat to Aston Villa seems a distant memory for the time being, at least. The Gunners were dominant against Fenerbahce in Istanbul, controlling play through Jack Wilshere, Santi Cazorla and the impressive Aaron Ramsey.
Arsenal are sure to qualify for the Champions League now, barring a disaster at the Emirates Stadium. Now Arsene Wenger must turn his attention to Fulham at the weekend - and strengthening his squad for another European campaign.
Having dominated the opening exchanges, Arsenal tested goalkeeper Volkan Demirel for the first time after 19 minutes.
Cazorla created the first opportunity for Walcott, his through-ball nearly finding the forward but Demirel slid in well to intercept.
The loose ball fell to Tomas Rosicky and he delivered a perfect cross for Giroud but the striker’s header was just wide of goal.
Fenerbahce were struggling to get into the game and failed to test Wojciech Szczesny in the opening half.
Wenger's early season injury problems continued just after the half hour when Laurent Koscielny was forced off with a head injury.
The French defender clashed with Pierre Webo and had to be replaced by Carl Jenkinson.
The hosts began the second half at a much higher tempo but fell behind six minutes in as Gibbs scored a crucial away goal, latching into Walcott's smart low drive across the box after holding off the challenge of two Fenerbahce defenders inside the penalty area.
Just after the hour, Arsenal doubled their lead thanks to Ramsey, receiving a pass from Jack Wilshere 35 yards from goal and moved at pace towards the Fenerbahce defence.
Ramsey drifted into a central position, and let fly from the edge of the area to beat Volkan Demirel, who really should have done better.
The victory was secured with 14 minutes to play as Kadlec brought down Walcott inside the penalty area. Giroud made no mistake from the spot, sending Demirel the wrong way to complete a perfect night for Arsenal.