Alex Smith completed 18 of his 19 passes to set up three touchdowns as San Francisco ran out 24-3 winners against their rivals.
NFL: Alex Smith guides 49ers to dominant victory over Cardinals
The San Francisco 49ers underlined their dominance of the NFC West with a 24-3 flattening of the Arizona Cardinals.
Alex Smith completed 18 of 19 passes for 232 yards and three touchdowns - two to Michael Crabtree and one to Randy Moss - as San Francisco (6-2) opened a two-game lead in the division and sent Arizona (4-4) to its fourth straight lost.
Arizona had got off to a good start while trying to end a three-game losing streak, with running back LaRod Stephens-Howling breaking free for a 24-yard reception on a screen pass in their first play.
But, like so many Cardinals drives this season, the progress fizzled out and ended when John Skelton threw a pass that was nearly intercepted.
Arizona's second drive was even worse: three and out with a false-start penalty, minus-7 yards.
he 49ers moved 77 plays in 10 yards on their second drive, capped by a 3-yard touchdown pass from Smith to Crabtree, who grabbed the ball above the head of cornerback Patrick Peterson for the score.
David Akers added a 43-yard field goal in the second quarter and Smith found Crabtree again with just under 2 minutes left, this time on a 9-yard pass after Arizona's defenders lost track of the San Francisco receiver.
The 49ers scored on their opening possession of the third quarter, too, when Randy Moss darted and dashed through Arizona's flailing defenders for a 47-yard touchdown pass that put San Francisco up 24-0.
Smith's only incompletion was dropped by a wide-open receiver.
Meanwhile the NFL has put back this week's trade deadline because of Superstorm Sandy.
The deadline had been set for later today, but has been moved to Thursday, NFL spokesman Greg Aiello confirmed.
The NFL's headquarters are in New York and will be closed both today and tomorrow, while several teams in or close to affected areas have shut down operations as well.