With both sides under pressure to recover from 2-4 starts to the season, Seattle displayed the stubborn defense they have missed for too long by forcing the home side to punt on their first six drives in the first half.
The Seahawks scored on their opening drive after winning the ball as Russell Wilson put together 12 plays before finally seeing Marshawn Lynch leap over from a yard out after he had already been held up by the 49ers, who had thwarted the away side five times within three yards.
There was concern for Seattle and Lynch in the first half when the running back was seen vomiting after battling a stomach bug throughout the day.
Good defense was on show from the Seahawks as Colin Kaepernick struggled to find any options with the ball in hand, and the Seattle lead was extended when Steven Hauschka converted a 49-yard field goal in the second quarter.
As Seahawks continued to dominate on the defensive end, Wilson took centre stage to tighten his side's grip on the game when he used time and space to deliver a 43-yard pass to Tyler Lockett, who collected on the run to score his first touchdown in the NFL.
After another 49ers punt, Wilson threatened to extend the lead when he sprinted out of the pocket to target Doug Baldwin, but Tramaine Brock intercepted the pass in the endzone to stop the home team from falling even further behind.