49ers 24, Cardinals 3: Alex Smith matched a career-high with three touchdown passes - two to Michael Crabtree - and visiting San Francisco's defense turned in another dominant effort in a primetime blowout of NFC West rival Arizona.

The 49ers (6-2) entered the game ranked first in the NFL in total defense and second in scoring defense, and they allowed only 297 total yards to move two games clear of Arizona (4-4) and Seattle in the NFC West. San Francisco has held four of its past five opponents without a touchdown after stopping Arizona's Larry Fitzgerald on the 1-yard line on fourth-and-goal with 49 seconds left.

Smith, who has won 20 of his past 25 starts, finished 18-of-19 for 232 yards, and his only incompletion was a drop by tight end Delanie Walker as he set an NFL record with a 94.7 completion percentage in a minimum 15 attempts. San Francisco improved to 14-0 when Smith starts and has a rating of 100 or higher.

The Cardinals, who have averaged nine points in four consecutive losses since starting 4-0, were limited to seven rushing yards on nine attempts. John Skelton was sacked four times, running Arizona's total to an NFL-high 39 sacks allowed this season.

Smith threw a pair of first-half touchdown passes to Crabtree to lead the 49ers to a 17-0 halftime advantage and Randy Moss turned a short pass into a 47-yard score to make it 24-0 with 7:27 left in the third quarter.

GAME NOTEBOOK: Moss has 18 touchdown catches in 19 career Monday night games, which ranks third behind Jerry Rice (34) and Terrell Owens (21). … Arizona's Daryl Washington recorded two sacks, giving him eight on the season - third in the NFL behind Houston's J.J. Watt (9.5) and Green Bay's Clay Matthews (nine). … Skelton dropped to 6-1 at home as a starter. He was 32-of-52 for 290 yards with no touchdowns and an interception.