49ers 13, Seahawks 6: Delanie Walker caught a 12-yard touchdown pass from Alex Smith with 4:29 remaining in the third quarter and Frank Gore rushed for 131 yards as host San Francisco extended its winning streak over NFC West-rival Seattle to four games.

David Akers kicked a pair of field goals for the 49ers (5-2), who rebounded from a dismal 26-3 home loss to the New York Giants on Sunday and moved a half-game ahead of Arizona for first place in the division.

With Seattle (4-3) clinging to a 6-3 lead, Alex Smith completed a short pass to Walker, who scampered toward the left pylon and got his left foot into the end zone before going out of bounds. It was the only catch of the game and fifth of the season for Walker, who had three touchdown receptions last season.

Gore, who appeared to suffer an injury late in the fourth, helped San Francisco control the quarter as he gained 65 yards on just four carries. His 20-yard run to the Seattle 16 helped set up a 28-yard field goal by Akers that provided the final margin.

San Francisco coach Jim Harbaugh made an interesting decision to decline a penalty against Seattle in the end zone on a fourth-down play with 43 seconds remaining that would have given his team a safety and a nine-point lead, electing instead to take possession and run out the clock.

Marshawn Lynch had 19 carries for 103 yards for the Seahawks, who allowed an opponent to gain 100 yards on the ground for the first time this season.

GAME NOTEBOOK: Smith completed 14 of 23 passes for only 140 yards, while Seattle's Russell Wilson was 8-of-22 for 106 yards. Both quarterbacks threw one interception. ... Seattle LB Malcolm Smith left the game after suffering a concussion on the opening kickoff. Smith, who led with his helmet while tackling Ted Ginn Jr., was helped from the field by team trainers. ... San Francisco WR Mario Manningham was inactive due to a shoulder injury. ... Akers extended his franchise record to 23 consecutive games with a field goal.