William Gallas opened the scoring after 43 minutes, and Gary Caldwell's own-goal 19 minutes from time ensured the visitors' superiority

Apart from the vital win, the Gunners have become the first European team to record a victory at Celtic since Nottingham Forest in 1983.

Both teams will meet again on August 26th at Emirates Stadium, and Celtic have to hit three goals without reply to qualify.

After the game, Arsenal manager Arsene Wenger voiced his satisfaction over his team's performance.

"I felt we had more control of the ball before we scored and they did not trouble us defensively but it was a real cup game today and we needed some mental strength to get through that," he told Sky Sports News.