SEATTLE — Two second-half interceptions helped the Seattle Seahawks pull away from the feisty St. Louis Rams and into the NFC’s top seed with a 20-6 win on Sunday.

The defending champion Seahawks (12-4) scored two touchdowns in a span of less than 2 1/2 minutes early in the fourth quarter to take a 20-6 lead in a game that helped secure a second consecutive NFC West title.

With the win, Seattle earned a first-round bye, at least one postseason home game and the right to host the NFC Championship Game if the Seahawks get that far.

Running back Marshawn Lynch rushed for 60 yards and the go-ahead touchdown on a 9-yard run that came after defensive tackle Jordan Hill’s interception, putting Seattle ahead 13-6 with 12:07 remaining.

Just over two minutes later, Seahawks linebacker Bobby Wagner broke up a pass that ended up in the arms of linebacker Bruce Irvin, who returned the interception 49 yards for another touchdown and a 20-6 lead.

The Rams marched down the field on their next possession but ended up turning the ball over again when Seattle safety Earl Thomas stripped the ball from running back Bennie Cunningham just in front of the goal line. The fumble rolled out of the side of the end zone, resulting in a touchback while giving the Seahawks possession.

Seattle had to rally from a 6-0 halftime deficit, due in part to two turnovers and a failed fourth-down conversion.

St. Louis quarterback Shaun Hill completed 26 of 37 passes for 243 yards and two interceptions. Seattle’s Russell Wilson was 17 for 25 for 239 yards and an interception.

The Rams (6-10) suffered a double-digit loss season for the first time since 2011, when St. Louis went 2-14.

The Seahawks will get a bye before hosting Detroit, Carolina or Arizona in the divisional round of the playoffs. Seattle went 7-1 at home this season and has gone to the Super Bowl in each of its two seasons as the NFC’s top seed (2005 and 2013). The Seahawks have won their past seven home playoff games, dating back to a January 2005 loss to the Rams.

Seattle looked in serious danger of repeating as NFC West champions when it opened the season with a 3-3 record and sat two games behind the Cardinals. But the season-ending knee injury to Arizona quarterback Carson Palmer opened the door for the Seahawks, which closed out on a six-game winning streak that saw opponents score just 39 points — an average of 6.5 per game.

Defense was the name of the game again Sunday, and Seattle had to rally after getting shut out in the first half.

St. Louis took a 3-0 lead on Greg Zuerlein’s 33-yard field goal, which capped off an 11-play drive with 6:25 left in the first quarter, forcing Seattle to rally from a first-half deficit for the fourth consecutive week. Zuerlein added a 52-yard field goal with 4:18 remaining in the first half, as the Rams went into halftime with a 6-0 lead.

Two costly turnovers helped slow down Seattle’s offense in the first half. The Seahawks outgained St. Louis 189-66 in total yardage and had twice as many first downs — eight to four — but got slowed by a failed fourth-down conversion, a Wilson interception and a Lynch fumble on three consecutive possessions.

Seattle’s first two drives of the second half resulted in Steven Hauschka field goals as the Seahawks tied the score 6-6 heading into the fourth quarter.

NOTES: Seahawks LT Russell Okung (bruised lung) returned to the lineup after missing last week’s game at Arizona. … Seattle S Jeron Johnson suffered a dislocated right elbow during a second-half kickoff return and went into the locker room with his forearm wrapped heavily. … Seahawks DT Jordan Hill, who had a tide-turning interception Sunday, did not finish the game because of a knee injury he suffered midway through the fourth quarter. Hill was able to walk off the field under his own power. … The Rams finished with a sub-.500 record for the eighth consecutive season.