Williams was frustrated with how they played on Saturday.
"We did brilliantly last week against Newcastle. This time I felt we took our foot off the pedal and let them back into it.
"As a dressing room we're frustrated. As a team we have to be better than that. We've got to continue to push ourselves, it's not about being safe.
"This was a game we could have won, we let it slip. We'll be disappointed if we don't finish in the top 10."