It's not out of the realm of possibilities that this one comes down to which team records more sacks. Both defenses rely heavily on their fronts to generate pressure -- the Giants with a four-man look led by Jason-Pierre Paul; the 49ers bringing a 3-4 attack paced by Justin Smith and rookie sensation Aldon Smith.
The Giants took down Aaron Rodgers four times last week in an upset win of Green Bay and have six sacks in two playoff games.
San Francisco, meanwhile, had three sacks of Drew Brees last week, with Justin Smith absolutely taking over the game at times.
"Whenever you have a leader like Justin Smith, one of your best players, your hardest worker, your fiercest competitor, that bodes really well for your football team," Jim Harbaugh said this week. "They watch the way he plays through some nagging hurts. It sets a tremendous tone -- a tremendous example for our football team."
Both of these teams finished in the top 10 in sacks during the regular season. But the Giants were much better in pass protection -- they allowed 28 sacks on the season to the 49ers' 44.
When these teams met in San Francisco in Week 10, it was a 31-yard Davis touchdown in the fourth quarter that helped turn the tables in the home team's favor. The 49ers went on to win that game 27-20, thanks to a late defensive stand.
Davis was an absolute terror for the Saints' defense to deal with last week, hauling in seven catches for 180 yards and two touchdowns, including the game-winner in the waning seconds.
New Orleans attempted to cover the talented 49ers tight end with safeties Malcolm Jenkins and Roman Harper. That strategy backfired in a big way. New York may use a small army, including safety Antrel Rolle and any number of linebackers, to try to slow Davis down.
"Keep giving them different looks," linebacker Michael Boley said of the Giants' game plan against the 49ers. "Don't give them something to key on. Keep giving them different looks, keep them off their game, and try to keep them off balance."
Combined with a huge Week 17 performance against the Rams, Davis has 15 catches for 298 yards in his last two outings.
The Giants' leading rusher did not play in the first meeting between these teams this season. Brandon Jacobs wound up leading New York with 55 yards rushing on 18 carries, while D.J. Ware added 34 yards on nine attempts. Bradshaw's healthy and has reclaimed his role as the No. 1 back in the Big Apple.
But will that matter against the 49ers' run defense, which allowed just 77 yards per game in the regular season?
New York has to hope so. If the Giants aren't able to establish at least a little success on the ground, it will open the door for those ferocious San Francisco pass-rushers to come full bore at Manning. Even finding a little success on the ground -- like the Giants did in Green Bay last week, as Bradshaw rushed for 63 yards and Jacobs found the end zone -- would add some critical balance to the visitors' attack.
San Francisco allowed just 37 yards rushing to New Orleans last week, but did cough up back-to-back 100-yard rushing games to Seattle and St. Louis to close the regular season.
The last Giants-49ers playoff game was an absolute classic. In the wild-card round on Jan. 5, 2003, San Francisco stormed back from a 38-14 deficit behind Jeff Garcia and won the game, 39-38, on a late Garcia-to-Tai Streets touchdown pass, marking the second-biggest comeback in NFL playoff history.
Sunday will be the latest chapter in what was, at one point, among the NFC's more interesting rivalries. The Giants and 49ers met six times in the postseason between 1981 and 1993, with each side scoring three victories. In four of those years, the winner of the Giants-49ers matchup went on to capture a Super Bowl crown.
Here's a look back at those six games:
The NFL has become a high-powered, pass-happy league over the last couple of seasons, but this game has all the makings of a physical, in-the-trenches fight. New York will do what it can to stretch the field, especially given that the 49ers' run defense was far and away the league's best during the regular season.
But will Manning have time to find Victor Cruz, Mario Manningham, Hakeem Nicks and the rest of his weapons? Or will Justin Smith and the 49ers' pass rush disrupt the Giants' entire offensive game plan?
When the 49ers are on the field, despite Alex Smith's breakthrough showing against the Saints, expect there to be a lot of run plays for Frank Gore. Like San Francisco, New York will bring a heavy pass rush at Smith when he drops to pass and, aside from the dynamic Davis, he does not have the weapons that Manning has to work with.
Given the 49ers' defensive prowess and the high level with which the Giants have been playing, it's hard to see either team running away on Sunday. And even though Smith bested Brees last week when it counted, give the edge to Manning in a close contest.