Arsene Wenger has said that Arsenal undermined themselves with an "extremely poor" defensive performance in last night's 5-1 Champions League defeat at Bayern Munich.

It was a first-half horror show for the Gunners at the Allianz Arena as goals from Robert Lewandowski, Thomas Muller and David Alaba saw the hosts lead 3-0 within 45 minutes.

Arjen Robben and Muller completed the scoring, either side of Olivier Giroud's consolation, to bring Arsenal back down to earth after their 2-0 win over Bayern in the reverse fixture two weeks ago.

"You have to give credit to Bayern first for their quality and on top of that we made things quite easy for them," the Frenchman admitted to Arsenal's official website.

"It was a bad defensive performance and we were extremely poor defensively. We were not at the races. The funny thing is that when we went forward we created good chances.

"We had a chance to score early but with a defensive performance like that, you go nowhere."

Arsenal sit third in Group F, six points behind co-leaders Olympiacos and Bayern with two games to play.