GLENDALE, Ariz. (AP) Alex Smith threw two of his three touchdown passes to Michael Crabtree and San Francisco stifled Arizona's offense, giving the 49ers a 24-3 lead over the Cardinals after three quarters Monday night.
San Francisco had its way with Arizona's defense, helped by some shoddy tackling by the Cardinals.
The 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 hit 17 of 18 passes for 233 yards the first three quarters, his only incompletion a dropped pass by Delanie Walker.
Arizona 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 the Cardinals' 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.
The Cardinals had 22 yards in the first quarter and were only marginally better in the second, finishing the first half with 69 yards. Skelton's up-for-grabs pass at the end of the half was intercepted, setting off a chorus of boos from the hometown fans.
Arizona finally moved the ball late in the third quarter, setting up a 28-yard field goal by Jay Feely that had the crowd booing again.
Skelton was 21 for 33 with 194 yards through three quarters.
Arizona's struggles were no surprise; Monday nights have been a horror show for the Cardinals since moving to the desert in 1988.
Arizona has lost seven of eight under the spotlight and two of those were memorably ugly for what happened after the game.
In 2006, Cardinals' coach Dennis Green had one of the NFL's biggest meltdowns, shouting ``They are who we thought they were!'' during his postgame news conference after a loss to the Bears.
Arizona quarterback Derek Anderson did his best Green imitation in 2010, when he shouted ``Nothing's funny to me!'' after a reporter repeatedly asked him why he was smiling during the closing seconds of blowout loss to the 49ers - Arizona's last game on Monday Night Football.
On the field, this NFC West showdown figured to be a physical beatdown.
For one, these two teams don't like each other much, trading insults before the games, blows once they started.
They also have two of the NFL's best defenses, aggressive units that try to knock opponents senseless.
The 49ers came in with the league's best defense, a punch-you-in-the-mouth group led by a dominating front seven that includes three All-Pros: defensive tackle Justin Smith and linebackers Patrick Willis and NaVorro Bowman.
San Francisco entered Monday night's game tied with Chicago for the NFL's best scoring defense, allowing 14.3 points per game, and has held three teams to 115 yards passing or less.
Arizona has the NFL's seventh overall defense and is third in scoring at 16.9 points per game. The Cardinals have been an opportunistic bunch, too, creating 15 turnovers the first seven games.
Arizona got the first good lick against San Francisco in the first quarter, when cornerback Patrick Peterson laid out 49ers receiver Mario Manningham on a screen pass.
The 49ers pushed right back, rolling over the Cardinals' defense while their defense stuffed one of the NFL's worst offenses, holding Arizona to four first downs and 6 yards rushing in the first half.