Just four days after producing only a field goal in a one-sided loss to the New York Giants, San Francisco managed just a single touchdown against the Seahawks.
It was the only touchdown by either team, however, and boosted San Francisco into the lead of the NFC West with a 5-2 record -- a half game in front of Arizona (4-2) and a full game ahead of Seattle (4-3).
Seattle took a 6-3 halftime lead on field goals of 52 and 35 yards by Steven Hauschka, but Smith led the 49ers on an 86-yard march that used up more than 6 minutes of the third period.
His throw to Walker gave San Francisco a 10-6 lead and the 49ers' David Akers added his second field goal of the game with 5:24 to play in the fourth quarter.
Smith completed 14-of-23 passes for 140 yards with one interception while Frank Gore ran 131 yards on 16 carries. Gore has 501 rushing yards for the season.
Seattle rookie quarterback Russell Wilson struggled against the San Francisco defense, ranked first in the NFL. He was good on only 9-of-23 passes for 122 yards and an interception. It was the lowest yardage production of the season for Wilson.