Gaffer's verdict: Lambert - Mistakes get punished at this level
Clark dwelled on the ball too long and let in Edin Dzeko, who fed Carlos Tevez for the easiest of finishes past Brad Guzan.
Lambert was gutted at the manner of the decisive moment but remained positive with ten games remaining in the survival fight.
He said: "I thought we were well in the game. The goal is a mistake. I wouldn't have minded if someone had put one in the top corner with a bit of skill. But it's a mistake by us.
"There was only minute to go. It is easy to be critical of Ciaran. The lad has been excellent all season. He will learn from it, he won't make the same mistake again.
"I just think he has tried something he maybe shouldn't have, feeling confident, but he has excellent for me throughout the games.
"I had a chat with him at half-time. It is easy to go in and absolutely take the paint off the wall. I knew that wouldn't do him any good.
"When someone makes a mistake - a genuine brilliant -and with how young he is, I thought he responded brilliantly in the second half. He didn't let it affect him, which was great.
"But when you're playing at this level and you make mistake with the calibre of strikers you're playing against, you know that's what can happen.
"But I thought we were well in game. I thought the whole team started well. We were on the front foot for long spells.
"Brad started to make saves towards the end of half, other than that, we were well in the game.
"I thought we might have had a penalty. I thought it was handball.
"But that's football. You pick yourself up and go again."
Lambert is certainly positive ahead of the run-in.
He continued: "Even last week I couldn't ask anymore against Arsenal.
"Tonight we came out and gave it a right good go.
"The next two games are massive for us. If we play like that, we will give teams a fright that's for sure."
When told of Roberto Mancini's post-match comments that he felt Villa would stay up, he added: "So do I.
"If we keep playing like that, we will."
Lambert also confirmed that he hopes to have Ron Vlaar available for the away trip to Reading next Saturday.
He added: "Hopefully Ron will be okay for Saturday. He wasn't too far off it, still a bit early.
"But hopefully we will see how this week comes and he will be okay."
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