Published: Oct 18, 2012 10:02 PM EDT
Updated: Oct 19, 2012 6:32 AM EDT

SAN FRANCISCO (AP) - Steven Hauschka kicked two field goals and the Seattle Seahawks took a 6-3 halftime lead over the San Francisco 49ers on Thursday night with first place in the NFC West at stake.

On a relatively warm and windless night at Candlestick Park, two of the NFL's top defenses dominated. Hauschka made field goals of 52 and 35 yards. He also missed wide left from 51.

Alex Smith and San Francisco struggled to move the ball for the second straight week, settling for a 38-yard field goal by David Akers in its best drive. Seattle outgained San Francisco 177 yards to 115.

The three-way tie atop the NFC West - with San Francisco, Seattle and Arizona all with 4-2 records - was set to be broken. The St. Louis Rams are 3-3.

Defense has been perhaps the biggest turnaround for a division some called the NFC Worst a couple of years ago. Seattle (15.3) and San Francisco (15.7) rank second and third, respectively, in points allowed per game.

Thursday night was no different.

Russell Wilson led a 10-play, 62-yard drive that started from its own 4-yard line before San Francisco shut down Seattle and Hauschka kicked his first field goal. Wilson completed 6 of 13 passes for 103 yards in the half to help Seattle score first for the seventh straight game to start the season.

Michael Crabtree caught a 16-yard pass from Smith on San Francisco's second drive, placing his hand on the ground to avoid going down and making three defenders miss along the sideline. The completion moved the 49ers to the Seattle 19 before the All-Pro Akers kicked the tying field goal late in the first quarter.

San Francisco moved the ball into Seattle territory on the game's opening drive on a 14-yard catch by Randy Moss, whose repetitions looked like they might increase early with starter Mario Manningham inactive with a shoulder injury. Then Smith threw incomplete twice between a short run by Frank Gore and the 49ers were forced to punt.

Gore had six carries for 39 yards.

San Francisco safety Dashon Goldson got a 15-yard unsportsmanlike conduct penalty for jawing with Marshawn Lynch during Seattle's first scoring drive. Lynch, who ran for 107 yards in the last meeting as San Francisco's streak of not allowing a 100-yard rusher ended at 36 games, had 55 yards on nine carries at the half.

Ted Ginn Jr. returned a punt 38 yards to midfield with 1:27 remaining before halftime. Smith threw the ball away twice under pressure before Bruce Irvin sacked him on third down to force a punt.

Malcolm Smith left with a concussion after making a hard, helmet-first tackle on Ginn during the opening kickoff. Seattle's backup linebacker was helped off the field by trainers and the team said he would not return.

San Francisco was looking to rebound from an embarrassing 26-3 defeat at home last week to the Super Bowl champion New York Giants, the most lopsided loss under coach Jim Harbaugh. The 49ers are 4-0 after a loss in Harbaugh's tenure.

They also swept the season series against Seattle last year for the first time since 2006.

The brewing rivalry between the last two division champions only heated up when Harbaugh and Seattle's Pete Carroll were reunited on opposite sidelines last year. Harbaugh has won the last three against Carroll.

That streak goes back to Harbaugh's win at Stanford against Carroll's Southern California team in 2009, when the Cardinal routed the Trojans 55-21. Harbaugh even had his team attempt a late 2-point conversion with the game out of reach that prompted Carroll's infamous midfield confrontation afterward, asking Harbaugh, "What's your deal?"

____

Antonio Gonzalez can be reached at: www.twitter.com/agonzalezAP

____

Online: http://pro32.ap.org/poll and http://twitter.com/AP_NFL