Charlie Whitehurst threw a touchdown pass on the game's opening drive and Seattle's defense made it stand up as the Seahawks clinched the NFC West title with a 16-6 victory over the visiting St. Louis Rams on Sunday night.
Olindo Mare kicked three field goals as Seattle (7-9) became the first team to advance to the NFL playoffs with a sub-.500 record.
The Seahawks, who had lost three straight and seven of nine, will host the defending Super Bowl champion New Orleans Saints next Saturday at 4:30 p.m. EST.
Whitehurst, making his second career start in place of an injured Matt Hasselbeck, threw a 4-yard touchdown pass to Mike Williams to cap a six-play, 87-yard opening drive. Ruvell Martin had a 61-yard catch to set up the score.
Seattle's defense took it from there, limiting the Rams (8-8) to a pair of field goals by Josh Brown in avenging a 20-3 loss at St. Louis in Week 4.
Of the Rams' first 11 possessions, the Seahawks forced nine punts and surrendered the two field goals.
Whitehurst finished 22 of 36 for 192 yards in outplaying Rams rookie quarterback Sam Bradford, who was 19 of 36 for 155 yards and an interception.
St. Louis, which went 1-15 last season and 6-42 over the past three seasons, pulled within 7-6 on Brown's 27-yard field goal with 8:59 left in the third quarter.
Mare extended the lead to 10-6 with a 31-yard field goal just under six minutes later. His third field goal, which followed an interception of Bradford by Will Herring, put the game out of reach with 1:37 to play.