And the former Man United trainee will be hoping he got it out of his system before the big Carling Cup clash against Sir Alex Ferguson's men.
In the last minute of the first half Yeovil's Arron Davies floated over a left-wing corner. It looked a regulation catch for Williams, who had done some good work earlier, but the keeper pushed the ball over his shoulder and into the net.
It was just the break the Glovers needed. Although they had earlier created the better chances, they had their work cut out to hold the highest scoring attack in the division, with teenager Nicky Maynard looking to add to the eight goals he had already scored.
Goals always looked likely. In the seventh minute Crewe's Rodney Jack was robbed by a last-ditch tackle from Mark Lynch when a goal looked likely, and two minutes later Williams showed what a fine keeper he is by blocking Lee Morris' shot at point-blank range.
Jack tested Yeovil keeper Steve Mildenhall with a header and before the bizarre opening goal, Williams made another good save, this time from a Chris Cohen piledriver.
Crewe, who had won their last four games, pushed on at every opportunity in the second half without creating many clear chances and in the 71st minute they conceded a second goal that clinched their fate.
Again it came from a corner, this time on the right. Cohen's kick was flicked on by Terry Skiverton and Marcus Stewart got in a powerful header which Williams tipped on the underside of the bar.
Stewart claimed it was over the line when it came down, but the flag of the referee's assistant stayed down and Paul Terry squeezed the ball over the line through a forest of legs.
Five minutes earlier the powerful Cohen had weaved his way through the defence to set up a clear shooting chance but his low drive, the Williams' right hand, skidded past the post.
Substitute Michael Higdon came close to getting one back in the 74th minute, but Lynch again came to Yeovil's rescue with a firm block.