SAN FRANCISCO -- Rather than trying to make sense of the seemingly countless and confusing playoff scenarios, Padres shortstop Miguel Tejada decided to treat this critical series against the Giants a bit differently.

"For me, I've been treating these games like they're all playoff games," Tejada said. "We can't worry about who we might play. We can't worry about tomorrow. We don't have tomorrow."

Actually, they do -- and possibly a whole lot more.

The Padres, seemingly a distant outsider in the playoff chase two days ago, are now in prime position to earn a postseason bid after their second victory in as many days over the Giants, this time a 4-2 victory before a sold-out crowd of 42,653 at AT&T Park.

Playoffs? In the eyes of Tejada and his teammates, they've already begun.

"We've had Game 7 for the last two days now," Padres closer Heath Bell said. "Tomorrow's going to be Game 7 [again]. We're going to put it all on the line, not leave anything for Monday, give everything we have. We're going to need everybody tomorrow.

"We feel good about the win, but our job's not done yet. ... We need to go out there and beat the best team in the West tomorrow."

As it stands, going into Sunday's regular-season finale, the Padres (90-71) are one game back of the Giants (91-70) in the National League West and are tied with the Braves for the NL Wild Card lead.

So what does it all mean?

• If the Padres win and Braves win Sunday, there will be a three-team tiebreaker -- the first in Major League history. The Giants would face the Padres on Monday in San Diego for the NL West title. The loser travels to Atlanta for a game Tuesday with that winner being the Wild Card entry.

• If the Padres win and Braves lose, the Padres and Giants would tie for the West title. But because the Padres own a better head-to-head record against the Giants in 2010, the Padres would win the NL West and have home-field advantage in the first round against the Reds. In this scenario, the Giants would be the Wild Card entry.

• If the Giants and Braves win, the Giants win the NL West and the Braves are the Wild Card entry. The Padres would be finished for the season.

• If the Padres and Braves lose, the Padres would travel to Atlanta for a one-game playoff Monday to determine the Wild Card entry.

"This club is very resilient and we knew coming here that our destiny was in our hands ... it still is," Padres second baseman David Eckstein said.

To get to this point, to where the playoffs are again a legitimate possibility, all the Padres needed to do was, according to outfielder Will Venable, be themselves again, something that hasn't been easy to come by in a difficult five-week stretch.

"I think it's really validation for us," Padres outfielder Will Venable said. "... Validation in that even when we were struggling, when we were losing, that we never lost our ID as a team. We've been the same team the whole time."

That equated to run prevention, leaning on pitching and defense. Both came through on Saturday as Tim Stauffer allowed one run on three hits in 6 1/3 innings and the bullpen combined to get the last eight outs, with Bell earning his 47th save.

"His command and that he was able to locate all of his pitches," Padres manager Bud Black said on what made Stauffer successful. "Under these circumstances, and playing in a hostile environment, he pitched great."

Stauffer, who on May 10 had an emergency appendectomy in San Francisco during an off-day, struck out four and walked two in the game. Since moving from long relief to the rotation in early September, he has a 1.83 ERA in six starts.

"He was unbelievable," Venable said. "He has not only done everything they have asked from him, but he's done it well. He's gone beyond expectations. I think that everyone in here is really proud of him."

The Padres backed Stauffer (6-5) with two runs in the first inning, taking advantage of a wild Barry Zito (9-14), who issued two bases-loaded walks in the inning, to the Nos. 6 and 7 hitters in the lineup, Yorvit Torrealba and Scott Hairston.

"What we wanted to do with Zito was get his pitch count up," Eckstein said. "And since his breaking pitches are so good, we knew that we had to make him throw strikes. I think we've done a better job offensively of giving ourselves a chance to score."

San Diego scored another run in the third inning when, after Tejada and Adrian Gonzalez opened the inning with singles, Tejada scored when third baseman Pablo Sandoval made a throwing error.

The Padres almost had a fourth run in the inning, but plate umpire Mike Everitt ruled that Hairston was thrown out trying to go from first to third on a hit by Chase Headley before Gonzalez could cross the plate.

Zito was lifted after walking Stauffer to open the fourth. He allowed three earned runs on five hits and had four walks.

"It's tough," Zito said. "Coming into the series, we knew we had to take one and now it's coming down to the last game. Unfortunately, I couldn't put it away today."

The Giants are 5-12 this season against the Padres, who reached 90 wins for the fourth time in team history.

And so it all comes down to this, the final game of the regular season. That's all Stauffer and any of his teammates could have asked for.

"I think we've got a little extra life in us now," he said. "Coming in here, we had a couple tough losses. Winning [Friday] was huge, obviously, but the way we won today puts us right in the hunt.

"That's all we can ask for at this point in the year. You go to the first game of Spring Training and you say game 162 is going to matter. That's what you play for."