Even though Williams finished the day with a pair of touchdown grabs, his impact was marginal at best, thanks to the defensive efforts of Tillman, who shadowed the Seattle wideout the entire game.
"Coach [Lovie] Smith and coach [Rod] Marinelli came to me early in the week and told me they were going to match me up on No. 17," Tillman said.
Williams had four catches for 15 yards. In the first meeting with the Bears in Week 6, he made 10 receptions for 123 yards.
Tillman knows the Bears secondary must perform at a similar, or higher level, when they face the Green Bay Packers in the NFC Championship game at Soldier Field.
"They put on a hell of a performance [against Atlanta on Saturday night]," Tillman said. "I was looking at Aaron Rodgers, those receivers, they were balling. If they put on a performance like that next week, I think as a secondary we're going to have our hands full. They were balling. They are a good team.
"Great quarterback, can't say how enough how good he is."