The Ravens (5-2), meanwhile, missed star linebacker Ray Lewis, who was placed on injured reserve this week with a torn triceps. Terrell Suggs, last year's defensive player of the year, saw his first action since undergoing surgery on his right Achilles tendon last May. Suggs sacked Schaub in the first quarter and finished with three solo tackles.
Otherwise, Baltimore's defense seemed overmatched without Lewis and cornerback Lardarius Webb, who were placed on injured reserve this week. Safety Ed Reed, who acknowledged this week that he's been playing with a torn labrum in his right shoulder, left in the fourth quarter with a chest injury. Reed said he felt fine after the game.
"It's not the end of the world," Suggs said, "but it's not something we're going to take lightly, either."
Baltimore's offense didn't look any better.
Flacco was off-target and under pressure most of the game, Ray Rice was held to 42 yards rushing and no Baltimore receiver had a reception longer than 15 yards. Baltimore came into the game with a league-high 34 offensive plays covering at least 20 yards.
"We can still play great defense," Kubiak said, "and expect to do that the rest of the year."
"They played well. We didn't," Flacco said. "They played fast and we just weren't able to stand up to it today and give it a good fight."
The play seemed to ignite Houston's offense and Schaub, who needed about three series to find the weak spots in Baltimore's injury-ravaged defense. He found Johnson for a 12-yard gain, then connected with Kevin Walter for a 25-yard touchdown and a 9-3 lead.
J.J. Watt really got Houston rolling when he swatted a Flacco pass, his ninth defensed pass of the season. Joseph caught it and sprinted to the end zone, showing no ill effects from the groin injury that forced him to miss practice time last week.
Shayne Graham tacked on field goals of 33 and 29 yards to put Houston up 29-3, its largest halftime lead of the season.
Schaub completed 19 of 32 passes - 12 in a row in one stretch - in the first half. Flacco, meanwhile, went 7 for 20 and was sacked twice to go along with two interceptions.
Baltimore got help from a pass interference call on Joseph early in the third quarter, and Flacco found Tanden Doss for a 15-yard touchdown.
Houston turned its next series over to its workhorse running back to seep time off the clock. Foster carried seven times for 18 yards on the 7 1/2-minute drive and plowed into the end zone with 2:56 left in the third quarter. He came into the game leading the NFL in carries (149).
Notes: Texans WR Andre Johnson finished with a season-high nine catches for 86 yards. He set a franchise record by appearing in his 129th career game for the team. ... Watt was held to no sacks for the first time this season. ... The announced attendance was 71,708, the largest regular-season crowd in Texans' history. ... Baltimore rookie RT Kelechi Osemele was carted off the field in the second quarter with a brace on his right leg. The team said X-rays on his ankle came back negative and he returned to the game in the second half. ... Tucker has four field goals of at least 50 yards this season, a Ravens record.
Copyright 2012 by The Associated Press