Quarterback Russell Wilson scored three touchdown passes as Pete Carroll's team continued their progress at the top of the NFC West.
The visitors went ahead when the 24-year-old fired a 31-yard pass for Sidney Rice to touch down midway through the first quarter, before throwing 15 yards for Zach Miller to slide into the endzone and increase the lead to 14-0 early in the second quarter.
The Cardinals threatened a fightback when Jay Feely nailed a 49-yard field goal and Rashard Mendenhall burst over the line from three yards, but Steven Hauschka split the posts with a 51-year field goal moments before half time.
Feely kicked over from 52 yards in the third quarter, but Wilson replied by finding Kellen Davis with his third touchdown pass of the evening.
Marshawn Lynch extended the lead to 31-13 before the end of the third quarter.
The home side found it difficult to break down the Seahawks defence, with Feely and Hauschka trading kicks in the fourth quarter.