Brian Westbrook’s big games weren’t all in his rearview mirror after all.

The 31-year-old running back rushed for 136 yards and a touchdown in place of the injured Frank Gore and the San Francisco 49ers sent punchless Arizona to its sixth straight loss, 27-6 last night in a shower of boos from the Cardinals home crowd.

Gore left in the first half with what was later diagnosed as a fractured right hip.

That should mean a lot more work ahead for Westbrook, who had 9 yards on five carries all season. He ran 23 times in his 21st career 100-yard game, but first since Dec. 7, 2008, for Philadelphia against the New York Giants.

San Francisco, beaten at home by Tampa Bay 21-0 last week, improved to 3-1 since Troy Smith became starting quarterback and pulled within a game of co-leaders St. Louis and Seattle in the anemic NFC West.

Arizona, two-time defending division champion, has not lost this many in a row since dropping eight straight in 2006, Dennis Green’s final season as coach.

The 49ers rushed for 261 yards, by far their season high and the most allowed by the Cardinals this season.

Westbrook, who led the league in rushing in 2007, was released a year ago after eight often-spectacular seasons with Philadelphia, a move caused by a combination of his age and injury history as well as the $7.5 million he would have been due this season.

He signed with San Francisco on Aug. 16, but had hardly played at all until Gore went down yesterday.

"I just kind of bided my time, tried to stay fresh, tried to stay focused," Westbrook said, "and when I got my opportunity, make the most of it."

He was able to show what he still can do.

"I think we have a lot of young guys, some of them have seen some of the things I’ve been able to do over the course of my career, some of them just don’t know," Westbrook said. "They just see a guy running around the practice field. For me it meant a lot to have an opportunity to go out there and play and have an opportunity to have success."

The Arizona defense did not provide much resistance as San Francisco pushed around the home team at the line of scrimmage from the start.

Gore injured a hip in the first quarter and briefly tried to come back before going out for good in the second period.

He had 25 and 15 yards on his first two carries, a sign of things to come against an Arizona defense that entered the game last in the league in points allowed.

Smith didn’t need to pass much, completing 11 of 23 for 129 yards with one touchdown and an interception.

San Francisco, a team that has not scored more than 24 points in a game all season, led 21-6 at the half. The 49ers hadn’t scored that many by halftime in two years.

49ERS 27, CARDINALS 6

First quarter

SF–Crabtree 38 pass from T.Smith (Andrus kick), 9:35.

Ari–FG Feely 31, 5:56.

SF–Dixon 1 run (Andrus kick), :29.

Second quarter

SF–Westbrook 8 run (Andrus kick), 7:23.

Ari–FG Feely 39, 2:16.

Third quarter

SF–FG Andrus 38, 2:38.

Fourth quarter

SF–FG Andrus 26, 12:43.

A–62,308.

RUSHING–San Francisco, Westbrook 23-136, Dixon 14-54, Gore 5-52, Morgan 1-13, T.Smith 3-6, Norris 1-0. Arizona, Wells 5-13, Hightower 5-0, Anderson 1-0.

PASSING–San Francisco, T.Smith 11-23-1-129. Arizona, Anderson 16-35-1-196.

RECEIVING–San Francisco, Morgan 3-28, Crabtree 2-48, V.Davis 2-32, Ginn Jr. 1-11, Zeigler 1-10, Norris 1-5, Dixon 1-(minus 5). Arizona, Doucet 5-60, Fitzgerald 4-37, Breaston 2-22, Roberts 2-21, Stephens-Howling 2-13, Wells 1-43.

MISSED FIELD GOALS–San Francisco, Andrus 47 (WR), 37 (BK).