Alex Smith threw a pair of touchdown passes to Michael Crabtree and San Francisco stuffed Arizona's offense, giving the 49ers a 17-0 halftime lead over the Cardinals on Monday night.
San Francisco had its way with Arizona's defense early, rolling up 113 yards in the first quarter of a rare game with the roof open at University of Phoenix Stadium.
After stalling on their first drive, the 49ers moved 77 yards in 10 plays for 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.
Smith completed 14 of 15 passes for 146 yards and his only incompletion was a dropped pass by Delanie Walker.
Arizona got off to a good start while trying to end a three-game losing streak, with running b...