The Seahawks have a 10-3 lead on the Cardinals midway through the second quarter.
The teams traded red zone field goals before the Seahawks finally reached the end zone.
Geno Smith threw a 19-yard touchdown pass to Will Dissly with 7:06 remaining until halftime.
Seattle has 163 yards with Ken Walker rushing for 55 yards on 10 carries. Smith is 6-of-11 for 102 yards, and Dissly has two catches for 40 yards.
The Cardinals have 130 yards.
