SAN FRANCISCO - Maybe it was the ballpark. Maybe it was the pitcher on the mound. Maybe it was the sunlight. Whatever the reasons for the Phillies' offensive futility yesterday afternoon, the only thing that really matters is the ramifications.

After a 3-0 loss to Matt Cain and the Giants at AT & T Park in Game 3 of the National League Championship Series, the Phillies find themselves in perhaps their most precarious pre-World Series position of the past three seasons.

Down two-games-to-one in this best-of-seven series, they need to win three of the remaining four games, at least one of them coming in a stadium in which they have struggled to hit.

All of it sets the stage for a direly important Game 4 tonight, when righthander Joe Blanton will square off against rookie lefthander Madison Bumgarner in hopes of evening the series. In their past two NLCS series victories against the Dodgers, the Phillies took a stranglehold in Game 4, first riding eighth-inning home runs by Shane Victorino and Matt Stairs to a win in 2008, then getting a two-run, walkoff double by Jimmy Rollins in the bottom of the ninth in 2009. In both cases, the Dodgers were unable to regroup for Game 5, the Phillies outscoring them in the two clinchers, 15-5.

"I would say tomorrow is the biggest game we played so far," manager Charlie Manuel said after Cain outdueled Cole Hamels en route to the victory. "Today was the biggest game, but tomorrow becomes bigger. That's how I look at it."

How the Giants will react remains to be seen. Can an upstart squad that entered the series as a heavy underdog summon the same killer instinct that has characterized this Phillies team over the past few seasons?

And, conversely, can this Phillies team bounce back from a deficit it has rarely been forced to face?

Since 2008, the only other time they have lost two games in a playoff series was last year's World Series, when the Yankees led, 2-1 and 3-1, before ultimately eliminating them in six games.

But the Phillies haven't faced a team quite like these Giants, who have made up for their lack of offensive starpower with superb pitching and timely hitting. Both were on display yesterday. The backbone of the effort lay in the right arm of Cain, who stymied the Phils for seven scoreless innings, allowing just two singles while striking out five and walking three. On the few occasions he found himself in trouble, the 25-year-old knocked the Phillies right back on the ropes. Twice, he stranded a runner on second base by getting Chase Utley to ground out. In the seventh, he did the same with Victorino. The Phillies' best chance for a big inning came in the fourth, when Ryan Howard reached on a bloop single and Jayson Werth walked to put runners on first and second with one out.

But Jimmy Rollins flew out to left, and Raul Ibanez struck out to end the threat.

The Phillies finished the day 0-for-5 with runners in scoring position and are 2-for-19 in the first three games.

"The series is far from over," said Victorino, who drew one of the three walks issued by Cain. "We've still got a lot of games left. We have four games left to worry about things. We're not going to sit here and go home and sob over it, worry about what we haven't done. We need to worry about what we are going to do."

The difference, then, was that the Giants came through in the precious few scoring opportunities they encountered against Hamels. In the fourth, Cody Ross drove in his fourth run of the series with a two-out single, and Aubrey Huff followed with a ground ball past a diving Utley that extended the lead to 2-0. The Giants tacked on another run in the fifth thanks to a two-out one-hopper off the bat of Freddy Sanchez that jammed Utley and richocheted off his wrist into centerfield, allowing Aaron Rowand to score.

For the most part, Hamels was sharp, retiring the first nine batters he faced before Edgar Renteria touched off the pivotal fourth with a leadoff single. Hamels left the game in the top of the seventh for a pinch-hitter having allowed three runs on five hits with one walk and eight strikeouts on 101 pitches.

Cain, however, was nearly unhittable, and now the Phillies find themselves in a position in which they are accustomed to subjecting others.

By the end of tonight, they will either be down 3-1 or tied at 2-2.

"You have a chance to put a team back two games," Rollins said of the Giants' current spot. "If they are not too sure about themselves, they'll fold, and we've seen that happen a number of times. I think if that's going to happen, we won't fold. It would be nice if we can jump ahead of them, bring it back [tonight], win the next two games, go back home, shut it down."

For more Phillies coverage and opinion, read David Murphy's blog, High Cheese, at http://go.philly.com/highcheese. Follow him on Twitter at