HOUSTON (AP) -- Struggling quarterback Matt Schaub didn't make any major mistakes against St. Louis.
The rest of the Houston Texans picked up where he left off on Sunday.
Sam Bradford threw three touchdown passes, St. Louis added a score on defense and special teams and the Rams stunned the mistake-prone Texans with a 38-13 win on Sunday.
The Rams (3-3) were up 24-6 early in the third quarter before rookie Daren Bates returned Keshawn Martin's fumble on a kickoff return for a touchdown.
Rookie first-round pick Alec Ogletree pushed the lead to 38-6 when he took an interception by T.J. Yates back 98 yards for a touchdown. Yates was in after Schaub sustained an apparent right ankle injury.
Schaub didn't have a turnover after throwing six interceptions, three of them returned for touchdowns in the past three games.
But several other Texans had key gaffes as preseason Super Bowl hopeful Houston (2-4) lost its fourth straight game.
The Texans had 95 yards of penalties, lost two fumbles and Yates threw two interceptions. Schaub had 186 yards passing and Yates finished with 98 yards passing.
Bradford was 12 of 16 for 117 yards. Rookie Zac Stacy had 18 carries for 79 yards in his second straight start.
Brian Quick's 4-yard touchdown reception extended the Rams' lead to 24-6 early in the third quarter.
Rodney McLeod forced the fumble by Martin on the ensuing kickoff and Bates, an undrafted free agent, scooped it up and returned it 11 yards, diving into the end zone for the score.
Schaub was injured on Houston's next drive when he was sacked by Chris Long. He remained on the turf for a few minutes before trainers helped him as he hobbled off the field.
He was replaced by Yates. Schaub had thrown an interception that was returned for a touchdown in four straight games entering Sunday.
Yates made it five in a row for Houston when his first drive ended with the interception return by Ogletree, who high-stepped his way into the end zone as the home fans serenaded the Texans with boos.
The Texans did not immediately provide any information on Schaub's injury, but he did not return.
The Rams took a 7-0 lead in the first quarter when Cory Harkey grabbed a 2-yard touchdown pass from Bradford. Houston's first big mistake came early in that drive when Kareem Jackson received a 40-yard penalty for pass interference.
The Texans were driving later in the first when Ogletree forced a fumble by rookie DeAndre Hopkins at the end of a 12-yard reception. James Laurinaitis recovered it and returned it 43 yards.
The Rams were unable to move the ball after the fumble and settled for a 42-yard field goal by Greg Zuerlein to push the lead to 10-0 early in the second quarter.
Houston cut the lead to 10-3 with a 20-yard field goal by Randy Bullock.
Another 2-yard pass by Bradford - this one to Lance Kendricks - extended the lead to 17-3. An unnecessary roughness penalty on Brian Cushing for a late hit on Bradford helped that drive.
Houston settled for another field goal just before halftime when Schaub's pass on third down fell incomplete to make it 17-6 at halftime.
About the only highlight for Houston on Sunday was the play of Arian Foster, who finished with 20 carries for 141 yards. He added four catches for 57 yards.
Ben Tate scored Houston's only touchdown on a 1-yard run in the fourth quarter.