'Last stand' looms for two faces of floundering team

(12-11) 19:42 PST -- An entire season of benched quarterbacks, AWOL players, a curb-sided offensive coordinator, road-killed away games, ownership playoff predictions and news conference rants comes down to this.

Win, or the 49ers will be eliminated from the postseason for the eighth straight year; win, or the head coach can start expecting to be get pink-slipped by season's end; win, or the door is bound to slam the franchise quarterback on his way out to free agency.

Fitting then, how coach Mike Singletary, quarterback Alex Smith and their 49ers must make their final Custer stand against the very Seattle team that kicked them down this steep slope's edge in the first place in a 31-6 season-opening loss at Qwest Field.

"They absolutely know what's at stake," Singletary said about today's Niners-Seahawks rematch at Candlestick Park. "It's a division game and it gives us the opportunity to stay in the hunt. That's all you can ask for."

The 49ers can't believe it's really come down to this. So many Pro Bowlers, so many returning starters, so much coaching continuity, so much promise after an 8-8 season ... only for it to go down like this?

They're 4-8 with four games to play, two games behind the Seahawks and Rams in an NFC West devoid of a winning team.

If they lose to the Seahawks, they're done. Even if they do beat the Seahawks, they still have plenty of hill to climb with consecutive trips to San Diego and St. Louis.

To think, last time the 49ers and Seahawks played, the 49ers were considered the juggernaut of unbeaten preseason lore and the Seahawks were the down-and-outers lined up at Square 1.

"Everybody came into that game thinking we were going to come to Seattle and shut them out," outside linebacker Ahmad Brooks said. "We went undefeated in the preseason and we have a great team and you look at the list, we've got a lot of superstars, a lot of athletes.

"We were just a little bit overconfident."

The start of the Seattle game did nothing to dissuade them. Cornerback Nate Clements intercepted a Matt Hasselbeck pass on the first snap of the game. The 49ers were inside the Seattle 10 on their first three possessions.

Then, four Seattle touchdowns in 7 game-minutes later, the 49ers were tumbling headlong into an 0-5 hole from which they have yet to scale their way out.

"It was shellshocking," inside linebacker Takeo Spikes said. "I remember it like it was yesterday. They just beat us."

Nose tackle Aubrayo Franklin said, "It sticks in the mind a little bit." Smith admits it left "a bad taste in all of our mouths from that game."

As far as elimination games go, it's only right the Seahawks are on the other side of the rope. This is the 49ers' chance to make things right again. If the regular season was spoiled by the first game, maybe the do-over can launch the 49ers toward the second season.

Much has changed in the 11 games since. Mike Johnson runs the offense, and not fired offensive coordinator Jimmy Raye. Brian Westbrook runs with the ball, not injured Frank Gore.

It still comes down to the same two faces of the franchise at the very core of this season - with Singletary pacing the sideline and Smith back at quarterback after five games on the bench.

However this shakes out, the two faces of the franchise rise or fall together.

"There's still an opportunity in front of us and an opportunity to win a game," Smith said. "That's all I'm thinking about."

E-mail David White at dwhite@sfchronicle.com.

This article appeared on page B - 1 of the San Francisco Chronicle