SAN FRANCISCO -- Cornerback Tramaine Brock intercepted two Matt Schaub passes and returned one for a touchdown, and the San Francisco 49ers routed the Houston Texans 34-3 Sunday night 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, and his total would be 10 if 49ers rookie safety Eric Reid held onto a pass that hit him in the hands late in the third quarter.
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.
The 49ers won their second consecutive game and improved to 3-2, a game behind the Seattle Seahawks in the NFC West standings.
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.
The Texans committed five turnovers to the 49ers' one, wiping out a 313-284 advantage in total yardage.
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.
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. The fourth-year pro 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, while quarterback Colin Kaepernick was just 6-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.
The 49ers built a 21-0 halftime lead, but Houston trimmed that advantage to 21-3 on Randy Bullock's 41-yard field goal with 12:01 left in the third quarter. San Francisco answered with Phil Dawson's 38-yard field goal with 5:15 remaining in the third, making it 24-3.
Then early in the fourth quarter, Kaepernick hit Davis with a 64-yard touchdown pass, increasing San Francisco's lead to 31-3. Lining up in the left slot, Davis angled toward the left sideline and no Texan covered him. Kaepernick threw a strike, and Davis raced down the sideline and into the end zone.
After 49ers safety Donte Whitner stripped Texans running back Ben Tate and cornerback Tarrell Brown recovered at the Houston 8, Dawson drilled a 24-yard field goal with 10:46 left.
Brock gave the 49ers a quick lead. 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 knifed in from the outside, picked off Schaub's pass headed to the end zone.
On their next drive, the Texans marched to the 49ers' 16 and faced third-and-1. However, tight end Owen Daniels was penalized for holding then for a false start, and Randy Bullock wound up hooking a 45-yard field-goal attempt wide left.
The 49ers took over on their 35 and marched 65 yards in 12 plays for a touchdown, Gore powering in from a yard out, to take a 14-0 lead with 1:37 left in the first quarter. Kaepernick completed four of six passes for 45 yards on the drive, hitting Davis twice for 24 yards and Anquan Boldin twice for 21.
The 49ers capitalized on Brock's second interception to take a 21-0 lead with 5:03 left in the half. This time Schaub telegraphed a pass along the left sideline to Johnson. Brock, in man-to-man coverage, tipped the ball into the air, caught it and raced 13 yards to the Houston 32. Johnson saved another pick-six, knocking Brock out of bounds.
Kaepernick scrambled for 14 yards on first down, and Gore gashed the Texans for 16 yards on second to the 2. Two plays later, Anthony Dixon hit left end and scored standing from 2 yards out.
NOTES: San Francisco DT Ray McDonald suffered a biceps injury and was ruled out midway through the third quarter. ... The 49ers' defense already was without two All-Pros, ILB Patrick Willis and OLB Aldon Smith. Willis missed his second consecutive game due to a strained groin, as Michael Wilhoite started in his place again. Smith sat out a second game in a row while undergoing rehab in the wake of his arrest last month on suspicion of driving under the influence of alcohol. Dan Skuta started in place of Smith again. ... Texans starting RG Brandon Brooks (toe) was inactive. Backup C/G Ben Jones started in his place. ... San Francisco and Houston met for just the third time overall and the first time since Oct. 25, 2009, a 24-21 Texans win at Houston.