Andre Johnson caught eight passes for 118 yards, and Foster scored for the fifth consecutive game for Houston (7-1).
Williams had a sack and five tackles in his return to Reliant Stadium after he signed with Buffalo (3-5) in the offseason. The Texans made Williams the No. 1 pick in the 2006 draft, and he's still Houston's career sacks leader (53).
Schaub won for the 10th time in 11 starts. He completed 19 of 27 passes for 268 yards and threw multiple TD passes for the second consecutive game.
Copyright 2012 by The Associated Press