SAN FRANCISCO -- The nightmare continued Sunday night for Houston Texans quarterback Matt Schaub, and the San Francisco 49ers took full advantage.
Cornerback Tramaine Brock intercepted two Schaub passes and returned one for a touchdown, and the 49ers routed the Texans 34-3 at Candlestick Park.
The Texans lost their third consecutive game and fell to 2-3, their first losing record since 2010. Schaub became the first quarterback since the NFL-AFL merger in 1970 to have an interception returned for a touchdown four games in a row.
Schaub completed 19 of 35 passes for a season-low 173 yards with three interceptions and a passer rating of 32.2. Schaub has nine interceptions for the season.
"We saw some things on film where he saw pressure and he would throw it off his back foot, look to his hot routes," 49ers safety Donte Whitner said of Schaub. "The one that Tramain got to run it back, was pretty much he thought he saw pressure. We were in a coverage and he jumped the route."
Backup quarterback T.J. Yates replaced Schaub with 14:11 left in the game and the Texans trailing 31-3. Yates completed three of five passes for 15 yards.
After the game, Texans coach Gary Kubiak said Schaub was still his starting quarterback.
"Hopefully that's rock bottom tonight," Kubiak said. "I'm trying to help my quarterback work through a very difficult time right now. I'm trying to help a guy I believe a great deal in."
Schaub said he appreciated Kubiak's support.
"A lot of confidence coming from the head coach," Schaub said. "We've been through a lot together and we're going to continue to go through a lot together. I'll fight tooth and nail for him and anyone in this locker room. We've shed a bunch of blood, sweat and tears and we're going to keep fighting. It's a long season. By no means is anything all said and done. We're going to keep fighting and come together."
The 49ers won their second consecutive game after dropping two straight and improved to 3-2, a game behind the Seattle Seahawks in the NFC West standings.
"I think this team is getting its confidence back," 49ers quarterback Colin Kaepernick said.
Brock picked off two passes in the first half, and 301-pound defensive tackle Tony Jerod-Eddie, dropping into coverage, intercepted a Schaub pass late in the third quarter.
Schaub wasted no time making pick-six history. Brock intercepted his first pass and returned 18 yards for a touchdown, giving the 49ers a 7-0 lead 90 seconds into the game.
Lined up in the right slot, Texans wide receiver Andre Johnson ran a quick out, and Schaub tried to hit him on third-and-6 from the 16. Brock left his man and knifed in from the outside on a "trap" coverage, picked off Schaub's pass headed to the end zone.
"We really didn't run trap all week, but we'd run it during training camp," Brock said. "It just came about. (Safety) Eric Reid called trap so we ran with it."
With 49ers nickel corner Nnamdi Asomugha out again due to a knee injury, Brock filled in for the second week in a row and made a strong case to keep the job. He entered the game with two career interceptions and doubled that total while scoring his first NFL touchdown.
Brock's second interception and 13-yard return to the Houston 32 set up San Francisco's third touchdown of the first half.
Frank Gore ran 17 times for 81 yards and a touchdown for the 49ers, Kaepernick was just six-for-15 for a season-low 113 yards and one touchdown, a 64-yard pass to tight end Vernon Davis. Kaepernick gave way to backup Colt McCoy with 6:01 left to play and the 49ers fully in command.
Texans running back Arian Foster carried the ball 21 times for 98 yards.