SAN FRANCISCO -- No Super Bowl champion ever has buzzed through its regular season without a three-game win streak.
The 49ers blew their fifth and final attempt at such a stretch last Sunday, losing 42-13 at Seattle to humbly extend the NFC West race.
Before they enter the playoffs, the 49ers (10-4-1) have one last chance to gain momentum: by winning the regular-season finale Sunday against the Arizona Cardinals (5-10) at Candlestick Park.
A victory also would secure the 49ers' second straight division title, and it would give them the NFC's No. 2 seed if the Minnesota Vikings (9-6) knock off the visiting Green Bay Packers (11-4). Both games kick off at 1:25 p.m. PST.
If the 49ers lose, they could still win the NFC West if the Seattle Seahawks (10-5) lose for the first time at home this season when they face the St. Louis Rams (7-7-1).
"That's a main objective: to play for the Western Division championship this week," 49ers coach Jim Harbaugh said. "And then also get a running start into the big championship. I think that's important."
The 49ers' last won the big championship (a k a the Super Bowl) 18 seasons ago. It will take at least three straight postseason wins to capture another one, and that would end the 49ers' disturbing trend of two wins followed by a loss or a tie.
A common theme in their four defeats: The 49ers didn't run like themselves. They're averaging 5.2 yards per carry, but in defeat, they averaged
Although the 49ers averaged a season-low 3.9 yards per carry in their 24-3 win at Arizona on Oct. 29, Sunday's rematch shouldn't be too challenging before the playoffs.
Brian Hoyer will become the Cardinals' fourth starting quarterback this season, and he'll be working behind a patchwork offensive line that's contributed to a league-high 56 sacks.
The 49ers defense, however, has caved during the absence of defensive tackle Justin Smith, who's out indefinitely with a partially torn triceps tendon. In their loss to the Seahawks, the 49ers allowed a season-high 42 points, 176 rushing yards and 11 third-down conversions.
Defensive coordinator Vic Fangio hasn't expressed panic nor has he publicly lambasted the culprits of his unit's recent woes. He also isn't infatuated with the concept of gaining momentum.
"Momentum is great, but it's tenuous," Fangio said. "You can get it back real fast, and you can lose it real fast. So, you've just got to keep playing."
As an example, Fangio cited the Baltimore Ravens' 33-14 upset win last Sunday against the New York Giants. The Ravens had lost their previous three games. "Zero momentum, and they blew out the Giants last week," Fangio added. "And now they've got momentum."
At least two more examples are worth considering. The 2009 Saints lost their final three regular-season games before winning their franchise's first Super Bowl, though they started 13-0. The 2008 Pittsburgh Steelers got blown out 31-14 in Week 16 at Tennessee but rebounded to shut out a hapless Cleveland Browns team 31-0 in the regular-season finale en route to winning the Super Bowl.
One of the great feats in the 49ers' two seasons under Harbaugh has been their bounce-back ability. They've never lost two consecutive games, and they followed their Nov. 11 tie with the Rams with a 32-7 rout of the Chicago Bears.
Such resiliency is a trait found in past champions. Of the 46 Super Bowl winners, 27 went through a season without losing back-to-back games.
That's the kind of Super Bowl history the 49ers might rather embrace than any talk of regular-season win streaks.
For more on the 49ers, see Cam Inman's Hot Read blog at blogs.mercurynews.com/49ers.