The win gave Seattle (9-4) its fourth consecutive NFC West title.
Marcus Trufant had three interceptions, returning his second one 84 yards for a touchdown.
Kurt Warner threw a career-high five interceptions on 28-of-46 passing. He also threw for three touchdowns in the loss.
Jerheme Urban caught six balls for 123 yards and a touchdown for the Cardinals (6-7), who despite the loss are one game behind Minnesota for an NFC wild-card spot.