ARIZONA - The San Francisco 49ers kept pace in the NFC West title race and dealt a blow to division rival Arizona's playoff hopes with a 27-6 victory over the Cardinals on Monday.

Brian Westbrook, coming in for injured running back Frank Gore, had 136 rushing yards to help the 49ers climb within a game of first place in the West despite owning a 4-7 record.

After starting the season 0-5, San Francisco now has a real chance of making the playoffs for the first time since 2002 as the two teams above it in the division - St Louis and Seattle - have 5-6 records.

Westbrook had carried the ball just five times before Monday's game but he took his chance when Gore went down with a hip ailment in the first quarter.

"I was fresh, only having five carries," Westbrook said after he recorded his first 100-yard rushing game since 2008. "I try to go out there and get ready every single week and this week I got the opportunity."

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.

The Cardinals committed their 27th turnover of the season on their first play from scrimmage when Derek Anderson and Beanie Wells botched a handoff and Aubrayo Franklin recovered for San Francisco. On the next play, Smith threw 38 yards to Michael Crabtree for the touchdown, the receiver making a diving catch in the end zone.

Wells gained a measure of redemption on the next possession. Playing as a wideout to the right, he caught a 43-yard pass from Anderson, but a season-long red zone problem continued and Jay Feely's 31-yard field goal made it 7-3.

Ted Ginn Jr had a kickoff return of 41 yards and a punt return for 42, both leading to San Francisco touchdowns.

The 49ers went 55 yards in 10 plays after the kickoff, Anthony Dixon leaping over from the 1-yard line to make it 14-3 with 29 seconds to go in the first.

Shane Andrus, kicking in place of injured Joe Nedney, missed a 47-yard field goal on San Francisco's first possession. He also had a 37-yarder blocked by Dominque Rodgers-Cromartie in the third quarter.

Arizona blew an opportunity late in the first half after Smith's pass bounced off the hands of Vernon Davis and was intercepted by Michael Adams at the San Francisco 42. Anderson threw three incompletions and the Cardinals punted. The boos that had started midway through the first quarter were louder than ever as the teams left the field.

LaRod Stephens-Howling briefly got the fans back into it with an 83-yard kickoff return to start the second half, but it was called back by a holding penalty against Arizona rookie Daryl Washington.

Reuters / AF