Albert Celades described Valencia's performance at Lille as their weakest in this season's Champions League after a dramatic late equaliser earned the hosts a 1-1 draw.
After Denis Cheryshev's goal put Valencia on course for three points at Stade Pierre-Mauroy, Mouctar Diakhaby was sent off for a second bookable offence, leaving the visitors with 10 men in the closing stages of Wednesday's game.
Diakhaby's dismissal gave Lille the boost they needed to find a way back into the match and Jonathan Ikone came off the bench to score a stunning goal in stoppage time.
Valencia head coach Celades slammed his side's display after they missed the opportunity to draw level with Chelsea and Ajax at the top of Group H, telling reporters: "I think that was our weakest performance so far.
"You got the feeling that the team wasn't at ease and that we weren't better in any area than Lille. Lille had a lot of chances. They were dangerous in a lot of situations.
"It's difficult to get out of a group like this, but we knew that each game would count.
"They caused us problems, particularly in the first half. We didn't play enough in their half of the pitch. We passed the ball around a lot, but in our own half. We wanted to play further forward, but it wasn't possible.
"We know we didn't play well, but Lille are a very good team. They have all my respect, but we know we can play better."
Lille counterpart Christophe Galtier admitted his side's hopes of progressing beyond the group stage remain slim after they picked up their first point of the campaign.
Galtier picked out the return fixture against Valencia on November 5 as a must-win for Lille, saying: "When you're in a competition, you want to go as far as you can, even though it's a very tough competition, and my players did everything they could to win. I am frustrated for them.
"I do not know if this match can revive us but it shows that we are progressing. We started from nothing in terms of experience and with experience comes progress.
"There are three games left and it will be necessary to win in Valencia."