The Seahawks (6-7) kept their fledgling playoff hopes alive with their fourth win in their past five games, but are still two wins back of the current wild card leaders.
If Seattle is to have any hope of getting into the postseason, it will have to win next week as it plays in Chicago against the Bears, who are currently one game up on the Seahawks.
The Rams (2-11), meanwhile, have fallen into a tie at the bottom of the NFC with the Vikings as they have dropped their past four games.
Tarvaris Jackson passed for 224 yards and a touchdown on 21-of-32 attempts while Doug Baldwin caught seven passes for 93 yards and a score and his block of a St. Louis punt set up the first touchdown for Seattle, which has won 13 of 14 over St. Louis.
Sam Bradford, who started after sitting out last week's game with a lingering ankle injury, went just 12-of-29 with 193 yards and an interception while Steven Jackson had a touchdown and 63 yards on 20 carries for St. Louis, which fell to 1-6 on the road.