The Niners can win if…

Under Jim Harbaugh, the 49ers have become a physical, unrelenting and efficient team that doesn’t make major mistakes. Last week, San Francisco used its offense to beat New Orleans, and it will need a similar performance on Sunday if the squad hopes to represent the NFC in the Super Bowl. Three keys…

1. Alex Smith has to deliver an encore performance

Not many people thought Smith would win in a head-to-head battle with Drew Brees, but that’s exactly what happened last weekend. Smith played his best game of the year, finishing with 299 yards and four total touchdowns (he only had seven games with more than 200 passing yards in the regular season). He was able to exploit the Saints’ blitzing scheme, but Smith will face a totally different defense against the Giants on Sunday.

You have to applaud Smith’s performance, but one game doesn’t make him the second coming of Dan Marino. The reality is the Niners had the worst passing game in the NFC during the regular season (just 183 yards per game) and relied on Frank Gore, who finished sixth in the league with 1,211 rushing yards, to move the chains. Even though the numbers weren’t flashy, Smith did his job, establishing career highs in passer rating and completion percentage, and hardly turning the ball over (his 1.1 interception rate was the best in the NFL).

San Francisco will need to get Gore going to alleviate some of the pressure on Smith. The Giants boast a lethal pass rush (48 sacks on the season) but can be beat through the air (29th ranked pass defense allowing 255 yards per game). Smith showed he can put up the numbers once, but he’s got to prove that he can do it again.

2. Converting in the red zone

The red-zone offense was a major Achilles heel for the Niners all year long, and unfortunately it hasn’t improved much during the postseason. In 54 trips to the red zone during the regular season, San Francisco scored touchdowns just 22 times — that’s an NFC-worst 40 percent conversion rate. In fact, that number got worse as the season progressed, with San Fran scoring just nine touchdowns in their final 29 possessions (33.3%).

The Niners were marginally better last weekend against the Saints (going 2-4), but they still settled for too many field goals (David Akers had three, including one from 25 yards out). San Francisco was lucky that didn’t come back to haunt them. This team is very good at protecting the football, finishing the year with league lows in interceptions and lost fumbles. But that won’t matter if you keep settling for three points instead of the full seven. The Giants have a good offense, so the Niners will have to convert touchdowns if they want to keep up.

3. Stay stingy on D

The strength of this Niners team is its defense, which finished the regular season ranked fourth in the NFL and tops against the run (a paltry 77.2 yards per game). San Francisco gave up the fewest points in the NFC (14.3) and the unit was even better at home, allowing just 10.9 points over the regular season.

The Niners faced a tough test last week, but for all intents and purposes they did quite well at defending one of the best offenses in the league, holding New Orleans to 472 yards (including just 37 rushing yards). But more importantly, they created five turnovers.

This San Fran D forces other teams to make uncharacteristic mistakes, something it will have to do again against New York on Sunday. The Giants offense has been clicking lately, but so was the Saints offense until it ran into the Niners. The D needs to stay aggressive and physical, keeping  Manning and the receivers guessing, and giving Smith a chance to win this game.