It was goalkeeper Foster who pulled off a string of superb saves to keep the scoreline respectable.
The former England goalkeeper completed a permanent move to the Hawthorns over the summer and Clarke was pleased with the 29-year-old's performance.
He said: "He made some good saves but you know when you are down to 10 men that the opposition will have chances against you.
"We spent a lot of time in the summer chasing Ben Foster because we know he is capable of making those types of saves.
"We know he is a top goalkeeper and we paid good money for him. Performances like that are what we expect from Ben Foster."