All season long, the Seattle Seahawks' defense carried them at times the offense sputtered. Its biggest challenge yet will come in Super Bowl XLVIII.

The Seahawks forced turnovers on the San Francisco 49ers' final three drives, the last an interception by Malcolm Smith on a deflection by Richard Sherman in the end zone with 22 seconds to go that sealed a 23-17 victory in Sunday's NFC Championship Game.

Next up: a title date with Peyton Manning and the high-powered Denver Broncos on Feb. 2 at MetLife Stadium in East Rutherford, N.J.

Colin Kaepernick fumbled and threw an interception on the 49ers' previous two drives. But the Seahawks scored only one field goal off those turnovers, keeping the game alive.

Given the ball once more with 3 minutes, 15 seconds to go, Kaepernick completed four consecutive passes, including a fourth-and-2 strike to crossing Frank Gore as the 49ers drove to the Seattle 18.

But Sherman got a piece of Kaepernick's jump-ball throw to the corner of the end zone and Smith corralled the ball in bounds, allowing Seattle to run out the clock and set off a celebration during which Sherman leaped into the stands at CenturyLink Field.

It's the second George Halas Trophy and Super Bowl trip in the 38-year history of the Seahawks, who also won the NFC title after the 2005 season before losing to the Pittsburgh Steelers in Super Bowl XL.