The French boss was not pleased to see his side throw away a 3-0 lead at the Emirates on Tuesday, putting their progression into the next round in danger

Arsenal boss Arsene Wenger has slammed his side's defense after the north London side threw away a 3-0 lead at home to draw 3-3 with Anderlecht in the Champions League, on Tuesday.

Goals from Mikel Arteta, in-form Chilean attacker Alexis Sanchez, and English midfielder Alex Oxlade-Chamberlain gave Arsenal a comfortable lead after 58 minutes as progression into the round of 16 appeared all but complete.

However, the 2006 runners-up saw their defense completely collapse as they conceded three goals, losing all hopes of finising top of their group to Bundesliga giants Borussia Dortmund, and will now have to fend off competition from Galatasaray and the Belgian side for the second qualifying spot.

“At 3-0, we thought the job was done,” the Gunners boss said. “It was fatigue, as well. They finished stronger and sharper. We got punished. Maybe, we subconsciously underestimated Anderlecht and we got punished. In the Champions League you need to be at the right mental level or you get punished. Certainly, we were not. Subconsciously, you can think the game is won.”

“We dropped off too much and we didn’t go into the challenges any more,” Wenger added. “Then, you are always open. We didn’t stop the crosses, the long balls. In the second half, it was bad defending more than being out-numbered.

“We gave a poor defensive performance from the first to the last. We never felt comfortable. There was a bit of bad luck because the first [Anderlecht] goal was offside but our defensive performance was not good enough. Across the pitch defensively, we were very, very poor.”

Arsene Wenger, Arsenal, Anderlecht, UEFA Champions League

Le Prof, who after 62 minutes had to remove club captain Mikel Arteta due to a hamstring injury, believes that the loss of the Spaniard played a huge part in the Belgian side's comeback. 

“When we lost Arteta we lost a bit today,” Wenger said. “He was one of the few who defended well.”

Arteta was also fuming after the final whistle, stating: “It is just not good enough. We have thrown everything away today. Even after conceding the first goal we still had a two-goal lead. It has blown our chances of winning the group and that is the main aim at the start of the competition.”