For the middle two quarters of Sunday's NFC West tilt, the San Francisco 49ers hung tough in Seattle, outscoring the Seahawks by three points.

Unfortunately for the men in red and gold, that encouraging midgame performance was sandwiched by a slow start and a shaky finish.

On the back of an overpowering rushing attack, the Sehawks handed the 49ers their seventh loss of the season, 29-13, at CenturyLink Field.

Seattle (5-4) outscored San Francisco (3-7) 19-0 in the first and fourth quarters.

Gabbert Strong Again in Defeat

Despite the loss, Gabbert showed quite well in his second start for the 49ers.

The quarterback, who now figures to line up under center for the remainder of the season with Colin Kaepernick on injured reserve, looked poised under pressure and orchestrated several sustained drives on Seattle's talented defense.

With a 98.2 passer rating, Gabbert nearly became the first San Francisco signal-caller to surpass the century mark in Seattle since J.T. O'Sullivan in 2008.

Trailing by three scores late in the first half, Gabbert led the 49ers on a nine-play, 92-yard touchdown drive spanning one minute and 31 seconds. He completed 6-of-7 passes for 78 yards on that possession.

Gabbert's best throws went to Quinton Patton for 15 yards on 3rd-and-7 and Anquan Boldin for 17 yards on 3rd-and-1. San Francisco capped the drive when Gabbert fired a rocket between two defenders to hit Garrett Celek in the middle of the field for a 19-yard touchdown. The score gave the tight end his first career score.

Gabbert and the 49ers offense attempted a comeback in the second half, but two successful drives stalled in the red zone and the team was forced to settle for field goals.

The final line for Gabbert? 22-of-34 passing for 264 yards and a touchdown. He was sacked twice.

Shaun Draughn, also in his second start for the 49ers, rushed 12 times for 37 yards and added eight catches for 40 yards.

Boldin, who returned after missing two games with a hamstring injury, paced the team with 93 receiving yards on five receptions.

Tackling Woes Haunt Defense

Seattle scored touchdowns on each of its first three possessions. The Seahawks marched down the field with a balanced run-pass attack, but the 49ers hurt themselves with substandard tackling.

One of the biggest beneficiaries of the missed takedowns was Thomas Rawls, who got the start with Marshawn Lynch inactive due to injury.

Rawls finished the afternoon carrying the ball 30 times for one touchdown and 209 yards, the most San Francisco has allowed in club history.

The rookie running back also caught three passes for 46 yards and another score.

Tyler Lockett, another rookie, scored Seattle's other two touchdowns. All three of the wideout's offensive scores this year have come against San Francisco.

Dorsey Exits Early

On Seattle's first offensive snap, Glenn Dorsey hurt his knee and needed to be carted off of the field.

The injury occurred away from the run play with little contact involved. Dorsey's right knee bucked and the lineman went down immediately.

In Dorsey's place, Arik Armstead received the majority of the snaps at left defensive tackle with Tony Jerod-Eddie also in the rotation.

Armstead had six tackles and a quarterback hit on the day.

Depth Chart Watch

For the first time this season, the 49ers had a new starter at right guard.

Instead of Jordan Devey, San Francisco gave the nod to Andrew Tiller, who made his season debut on Oct. 11 versus the New York Giants and has gradually picked up reps ever since.

Kenneth Acker returned to his starting role after missing the Week 9 win over the Atlanta Falcons with a concussion, but Marcus Cromartie replaced the cornerback midway through the first half. It did not appear that the switch was due to injury. 

Gold Nuggets

• The 49ers sacked Wilson twice, once by Ahmad Brooks and the other by Aaron Lynch and Quinton Dial. Brooks now has four sacks on the year, three of which have come on Wilson.

• In his first game at CenturyLink Field since suffering a severe knee injury in the 2013 NFC Championship game, NaVorro Bowman amassed nine tackles.

• With two made field goals on Sunday, Dawson has now connected on 16 attempts in a row this season.

• McDonald's 65 receiving yards eclipsed his season total (64) entering the game. The output also more than doubled his career high (25).

• Seattle outgained San Francisco 508-306. The 49ers went 2-for-11 on third down.