However, Williams has admitted that he should have done better with the back pass to Lewis Price.
"The conditions played a part in the back pass, the pitch was ridiculously bad," said Williams. "But I probably should have hooked it out, knowing what it was like.
"How many times do you pass the ball back to the goalkeeper and it is fine?
"It got stuck in the mud a little bit and it went in after that."
Wales sit fifth in Group A.