Smith hooked with up Crabtree on 3-yard scoring strike in the first quarter to open the scoring and found him again on a 9-yarder before halftime to establish a 17-0 lead.
Randy Moss also hauled in a 47-yard TD toss from Smith, who completed 18-of-19 passes for 232 yards with no interceptions for the NFC West-leading 49ers (6-2).
Crabtree finished with five grabs for 72 yards and San Francisco's defense held the Cardinals to just seven total rushing yards in picking up a second straight victory against a division opponent.
John Skelton went 32-of-52 through the air for 290 yards and an interception for Arizona (4-4), which dropped a consecutive game.
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