No, it's not over, but San Diego (88-71) now faces a steep uphill climb after falling three games back in the National League West race with three games to go.
The Padres, who have dropped four of their last five games, need to sweep the Giants to force a one-game playoff for the division title on Monday in San Diego. Atlanta, which was idle on Thursday, holds a two-game lead over the Padres in the NL Wild Card standings heading into its final regular-season series against the Phillies.
If the Padres take two of three from the Giants and the Braves are swept by the Phillies, the Braves would visit the Padres for a one-game tiebreaker for the Wild Card on Monday.
If the Padres sweep and the Braves lose two of three games, all three teams would be tied at 91-71, setting up a pair of one-game playoffs -- first for the NL West title on Monday, and then the Wild Card on Tuesday.
"We've got to win, no doubt about it," Padres manager Bud Black said. "It's right there in front of us. This is what you play for, to be in this situation, to play meaningful games the last week of the season. We just haven't played well enough to win them.
"We're still breathing. We've still got a chance. It's not over."
San Diego could only manage three hits against Cubs starter Tom Gorzelanny and relievers Andrew Cashner, Sean Marshall and Carlos Marmol on Thursday, with none of them coming after the second inning.
"We need to create some more opportunities [offensively], so it's not the one time that you come up that you have to get the job done," Padres third baseman Chase Headley said. "Early in the season, we created a few opportunities and someone would come up with it, because we didn't feel like we had to get it one that time, or we were not going to get another chance.
"We need to give ourselves a better opportunity to drive in runs."
Padres starter Jon Garland matched Gorzelanny pitch-for-pitch, tossing 6 1/3 shutout innings while racking up eight strikeouts. The bullpen also held the scoreless tie until the ninth inning, when Heath Bell allowed the game-winning run to score when Aramis Ramirez sent a broken-bat single to right, and pinch-runner Darwin Barney came home to score on a single to left by Brad Snyder.
It was Bell's first loss of the year in his 65th appearance.
"It wasn't my 'A' game," Bell said. "I'd rather have a loss the first game of the year, and not right now. I'll bounce back tomorrow and pitch the next three games, if the guys let me."
The Padres' best chance to score came in the sixth against Gorzelanny, when he walked David Eckstein and Miguel Tejada to start the inning. But the club that has so often had the knack for the clutch hit this season hasn't found that same magic down the stretch, as Adrian Gonzalez grounded into a double play and Ryan Ludwick flew out to center to end the threat.
"I was again looking fastball away, and he tried a little two-seamer in, but ended up yanking it," Gonzalez said of his double-play ball. "It looked like a fastball away, and it had good bite at the end and sunk down. He's never thrown me that pitch before, and he wasn't trying to throw that in that situation. He ended up making a pitch without trying to."
Those in the San Diego clubhouse maintain that the Padres still control their own destiny. And they're right.
But if the Padres are going to halt one of the bigger collapses in baseball history and prevent the Giants from celebrating a division title as early as Friday, they will have to quickly find a cure for their anemic offense.
That will be easier said than done against the Giants' trio of Matt Cain, Barry Zito and Jonathan Sanchez.
"We can go up there and win these three games and put ourselves in a position to still have this," Gonzalez said. "I think we play better when our backs against the wall. The main thing is that they've got great pitching, and that's going to be the challenge -- our offense against their pitching -- because our pitching is going to dominate. We've just got to go out there and score runs."