The Seattle Seahawks have picked up their third win of the season by beating the San Francisco 49ers 20-3 at CenturyLink Field.

With both sides starting the night with 2-4 records, Seattle produced the kind of defensive display which had been a regular occurrence in the last two seasons as they claimed a vital win to move up to second in the NFC West.

Dominant defense from the Seahawks was the key, with the 49ers being forced to punt on all five of their first-half drives as the home side gained just 46 yards total in the opening two quarters.

Marshawn Lynch, who was seen vomiting on the sideline at one stage in the first half, did the early damage on Seattle's drive as the away team bounced back from being halted five times inside three yards when the running back jumped over a number of bodies for the score.

San Francisco quarterback Colin Kaepernick never clicked with his offense on a night when he was sacked six times, and he appeared powerless to stop the Seattle charge as a 49-yard field goal from Steven Hauschka made it 10-0 early in the second quarter.

The 49ers had a mountain to climb when Russell Wilson produced a 43-yard pass to find Tyler Lockett, who took the catch on the run to complete the score for his first touchdown in the NFL.

Tramaine Brock's interception in the endzone just before the half-time break stopped Wilson from adding to the score, but there would be no big response from San Francisco when the players returned.

Wilson was unable to find the spark in the offense to make it an even more emphatic win, but the Seahawks took their time on drives to run the clock down quickly and the 49ers were forced to settle for a 35-yard field goal from Phil Dawson as they finally got on the scoreboard late in the third quarter.

The Seahawks continued to manage the game impressively as Hauschka ended a drive just before the seven-minute mark by splitting the posts with a field goal from 46 yards.

Pete Carroll's side had held a fourth-quarter lead in all four of their losses this season, but a dramatic finish was never on the cards as Seattle eased to the win, while the 49ers departed the field to jeers on a night when they recorded more punts than first downs against a Seahawks defense looking back to their best.