Mike Williams yanked down a career-high 11 passes for 87 yards and a touchdown for Seattle (4-2), which took over sole possession of first place in the NFC West with the victory.
Matt Hasselbeck went 20-of-38 passing for 192 yards and a score and Marshawn Lynch racked up 89 yards on 24 carries for the victors.
The Cardinals (3-3) struggled on offense. Max Hall could complete only 4-of-16 passes and was picked off once in the setback.
Derek Anderson relieved Hall and finished 8-for-17 for 96 yards.