Clarke was disappointed to concede a late goal but hailed a top-drawer performance from Foster.
The former England player bounced back from his poor performance against Liverpool in midweek with several fine saves.
Clarke said: "Having been in that position I'm a little bit disappointed we didn't go on and win it.
"Obviously, in an away game like this you probably need the second goal just to alleviate a little bit of the late pressure you know is going to come when the ball is going to be in your box a lot.
"But Ben Foster was excellent. I said the other night when he made the mistakes there was nothing to worry about - and he proved that today.
"He's a top goalkeeper and made one save in the first half off the deflected shot which was unbelievable, fantastic.
"You need your goalkeeper to make saves in the Premier League to help you get the points. He's up there with the best of them.
"Compared to some of the other keepers I've worked with Ben may be a little more unorthodox - but he makes the saves just the same.
"I've only known him for 12 weeks but he's been really good for us."