Arsene Wenger has slammed the 'suicidal defending' and 'weak mentality' of his Arsenal players following last night's shock home defeat against Monaco in the Champions League.

The Gunners struggled to get out of first gear all evening and now have it all to do in the second leg of their last-16 tie, having fallen 3-1 against the Ligue 1 outfit.

Monaco, of whom Wenger has previously taken charge for seven years, twice hit their opponents on the break to put themselves in the driving seat for a place in the quarter-finals of the competition.

"Congratulations to Monaco, they had a perfect result and played the game they wanted to play," the 65-year-old is quoted as saying by BT Sport. "On our side, I believe that we missed the chances and we were a bit suicidal defensively. We were not at the level defensively and we were a bit unlucky as well because the first goal is deflected.

"On the second and the third goal we were suicidal. We had the luck to come back to 2-1, but not the right to give away a goal the way we did because that makes our task extremely difficult in the second leg. It looks like we have lost our nerve and our rationality on the pitch.

"The heart took over the head and at that level it doesn't work. Our weakness was more down to mentality. We rushed our game, we knew coming back at half-time it was important not to concede a second goal and we were too impatient. Mentally we were not ready or sharp enough to get into this game. We paid for it."

Arsenal have failed to advance beyond this stage of UEFA's showpiece competition since 2010.