Alex Smith led a key drive to seal the win for San Francisco on Sunday night. Reuters

The San Francisco 49ers maintained their strong start to the season with a victory over another 2012 NFC playoff team as quarterback Alex Smith and the 49ers tough defense held off the Detroit Lions at Candlestick Park on Sunday night, 27-19.

In Week One, San Francisco defeated the Green Bay Packers at Lambeau Field, and the 49ers are currently only one of three teams in the NFC with a 2-0 record.

Smith completed 20 passes on 31 attempts for 226 yards and two touchdowns, and his fourth-quarter strike to tight end Vernon Davis helped seal the victory for Jim Harbaugh's squad.

It was an impressive drive by Smith, who led the offense from their own 21-yard line to the end zone on 13 plays. The touchdown gave the 49ers a comfortable 15-point advantage.

The Lions would respond with a touchdown minutes later, but their onside kick failed and the 49ers were able to end the game on possession. The Lions trailed the entire game, and were hurt by Matthew Stafford's first-quarter interception in Detroit territory, which led to a 49ers touchdown.

Detroit could have also used more production from their running game. The Lions rushed for a total of only 82 yards on 26 carries.

Running back Frank Gore ran for 89 yards on 17 carries for the 49ers.

One of the story lines heading into the game ended without controversy. In 2011, Lions head coach Jim Schwartz and 49ers head coach Jim Harbaugh got involved in a heated exchange during the post-game handshake following the 49ers close victory at Ford Field.

There was no problem on Sunday, as Schwartz and Harbaugh were quick to shake hands prior to the game and ended the game with a cordial response.