Click photo to enlarge
San Francisco 49ers Justin Smith (94) celebrates his sack and fumble recovery against the Pittsburgh Steelers in the fourth quarter at Candlestick Park in San Francisco, Calif. on Monday, December 19, 2011. (Nhat V. Meyer/Mercury News)

Defensive lineman Justin Smith sat in a dimly lit room with 49ers teammates last week and marveled at film of the New Orleans Saints' offensive fireworks. His reviews confirmed the obvious: The Saints "do some pretty awesome stuff on offense."

But Smith also found a blueprint that could help the 49ers shut down record-setting quarterback Drew Brees on Saturday, when their worlds collide in an NFC playoff divisional-round game at Candlestick Park.

"Defensively, we know we're going to have to pressure Brees, hit him, make him uncomfortable," Smith said. "You know, one of the games they lost this year was to St. Louis, and that's why (the Rams) won."

The previously winless Rams produced six sacks in a 31-21 upset of the visiting Saints on Oct. 30. At halftime, New Orleans trailed 17-0 and, according to Smith, Brees no longer could trick defenders by faking short passes and going deep.

Smith and the 49ers defense couldn't stop Brees' Saints in their last meaningful clash.

On Sept. 20, 2010, Brees engineered a game-winning drive at the end of regulation for a 25-22 victory in San Francisco on "Monday Night Football." The 49ers tied the score with 1:19 remaining, and the pass-oriented Saints marched down the field for a 37-yard field goal as time expired.

That 2010 defeat showcased the type of errors the 49ers have avoided this season. Alex Smith threw two interceptions, the 49ers lost two fumbles, and the Saints committed no turnovers. Also, then-center David Baas snapped the ball over Smith's head on the third play of the game for a safety.

This regular season: Smith had only five interceptions, and the 49ers led the league with a plus-28 turnover differential. They haven't committed a turnover in their past 22 quarters.

Saints coach Sean Payton, in his Sunday news conference, downplayed any link between that 2010 walk-off victory at Candlestick and this Saturday's rematch. The 49ers defense is stronger, and it has thrived under first-year coordinator Vic Fangio.

New Orleans (14-3) has not lost since that Oct. 30 game in St. Louis. Brees has never lost in five career games against the 49ers. He set up a sixth meeting by throwing for 466 yards and three touchdowns in Saturday night's 45-28 wild-card win over the visiting Detroit Lions.

Anticipating that result, 49ers coach Jim Harbaugh said Friday that Brees "is playing as well or better than anybody who has ever played the game."

Brees dismissed any suggestion the Saints are more vulnerable away from their Superdome, where they've gone 9-0 this season.

"I feel like our offense and our team is built for whatever condition," Brees told reporters Saturday night. " ... We feel like we're the type of team that should be able to go anywhere, anytime, and play our type of football that we know how to play.

"I don't see any reason why we can't go on and continue to be productive."

The 49ers led all NFC defenses in allowing the fewest yards (308.1) and points (14.3) per game. The defense boasts four players who made the Pro Bowl: Justin Smith, linebacker Patrick Willis, cornerback Carlos Rogers and safety Dashon Goldson.

"We're going to have to come with our A-plus-plus game against them," Saints left guard Carl Nicks told reporters Saturday night. "I'm going to go against Justin Smith, and he's a big dude."

Although the 49ers and Saints have never met in the playoffs, they faced off in this season's exhibition opener, a 24-3 win by the host Saints. Center Jonathan Goodwin chuckled last week in recalling the Saints' 18 first-half blitzes that game.

Goodwin played five seasons with the Saints before joining the 49ers this season, so he was accustomed to defensive coordinator Gregg Williams' blitzes, even in practices. "It's something we should have picked up," Goodwin said, "and part of that comes with experience in playing with each other."

Goodwin fondly recalled his time with Brees and their Super Bowl triumph two years ago: "For five years, I saw one of the greatest quarterbacks. He reads everything. He sees defenses like it's a piece of cake."

Goodwin's final snap to Brees came in a 41-36, wild-card playoff loss at Seattle. It'll now be up to Justin Smith and the 49ers defense to end another Saints season on the West Coast.

For more on the 49ers, see Cam Inman's Hot Read blog at blogs.mercurynews.com/49ers.