The Seattle Seahawks seek their fourth NFC West title in seven seasons when they host the division-rival San Francisco 49ers on Sunday Night Football. Kickoff from CenturyLink Field is set for 8:20 p.m. ET. The Seahawks (11-4) have lost two of their last three contests after falling 27-13 to Arizona at home last Sunday but will claim the division crown with a victory. Seattle, which has covered the spread in 33 of its last 51 games as an underdog, will have a familiar face in the backfield as Marshawn Lynch was signed after the team lost two running backs for the season in the loss to the Cardinals

San Francisco (12-3) is looking to avenge an overtime loss at home in Week 10 and clinch the NFC West - as well as the top seed in the conference. The 49ers have produced 104 points while winning two of their last three games, including a 34-31 home triumph over the Los Angeles Rams last week. 

San Francisco is a 3.5-point favorite and the over-under for total points scored is 46 in the latest 49ers vs. Seahawks odds. Before locking in any Seahawks vs. 49ers picks or NFL predictions, make sure to see what SportsLine expert Tom Fornelli has to say.

A CBS Sports writer since 2010, Fornelli is a consistent winner when it comes to against-the-spread and over-under NFL picks. And he has had a particularly keen eye for the 49ers. Fornelli has hit 12 straight picks involving San Francisco, including 10 in a row against the spread. Anyone who has followed him is way up.

Now, Fornelli has locked in on 49ers vs. Seahawks from every angle and released a confident against-the-spread pick. Head to SportsLine to see it. Here are the NFL lines and trends for 49ers vs. Seahawks:

  • 49ers vs. Seahawks spread: San Francisco -3.5
  • 49ers vs. Seahawks over-under: 46 points
  • 49ers vs. Seahawks money line: San Francisco -179, Seattle +154
  • SF: RB Raheem Mostert has rushed for a touchdown in five straight games
  • SEA: QB Russell Wilson is third in the NFL with 29 TD passes

Fornelli knows that the 49ers have gotten where they are with a unit that ranks second in the league in total defense (277.4 yards) and first against the pass (165.6). San Francisco also has had plenty of success getting to the quarterback and is fifth in the NFL with 47 sacks.

Mostert has helped boost the ground game of the 49ers, who are second in rushing offense with an average of 145.1 yards per contest. The journeyman, who suited up for five different teams over his first two NFL seasons, appears to have found a home in San Francisco and leads the club in rushing with 715 yards. Mostert is the fourth player in franchise history to run for a touchdown in five consecutive contests.

Still, San Francisco isn't assured of covering the Seahawks vs. 49ers spread on Sunday Night Football against a team that has been hit hard by injuries.

Lynch, who ran for at least 1,200 yards in four straight seasons for the Seahawks from 2011-14, was brought in due to season-ending injuries to leading rusher Chris Carson (hip) and C.J. Prosise (arm). The 33-year-old Lynch appeared in six games with Oakland last year, recording 376 yards and three touchdowns on 90 carries. The Seahawks also added another familiar face to their backfield in Robert Turbin, who spent his first three NFL seasons with the club and was a member of their Super Bowl-winning team following the 2013 campaign.

Seattle will need a strong performance from Russell Wilson, who has posted a quarterback rating over 100 just once in his last six games. Despite the team's 4-3 record at home, the seven-time Pro Bowler has played well at CenturyLink Field, throwing 17 touchdown passes and running for a pair of scores while being intercepted only twice. 

We can tell you Fornelli is leaning over the total, but his stronger play is on the spread. He's found a critical x-factor that makes one side of the spread hit hard on Sunday Night Football. He's sharing what it is, and who to back, only at SportsLine.

Who wins Seahawks vs. Niners on Sunday Night Football? And what critical x-factor makes one side of the spread a must-back? Visit SportsLine now to see which side of the 49ers vs. Seahawks spread you should be all over Sunday, all from the football expert who has hit 12 straight picks involving San Francisco.