Matt Cassel threw three touchdowns and the Kansas City Chiefs improved to 3-0 for the first time since 2003 with a 31-10 victory over the struggling San Francisco 49ers on Sunday.

San Francisco (0-3), a popular pick to win the NFC West, managed just 251 total yards and 11 first downs.

Cassel, who entered with a miserable 55.8 passer rating, helped the Chiefs turn a 10-3 halftime edge into a blowout.

He was 16 of 27 for 250 yards with touchdowns passes to Dexter McCluster, Dwayne Bowe and Tony Moeaki.

Bowe’s 45-yard touchdown catch extended the lead to 17-3 with 9:37 left in the third and Cassel hit Moeaki for an 18-yard touchdown with 1:41 left in the quarter.

Thomas Jones' 3-yard touchdown run capped the scoring for the Chiefs. Jones and Jamaal Charles combined to run for 192 of Kansas City's 207 yards on the ground.

Alex Smith was 22 of 41 for 220 yards with a touchdown and an interception for San Francisco, which was just 4-of-17 on third down.

The Chiefs continue to be one of the biggest surprises in the league. Kansas City can match its win total from last season with a victory next week.