SAN FRANCISCO (AP) -- Roy Halladay pulled his groin in the second inning and most of his teammates had no idea.
The pitcher just stuck it out like the ace he is for the Philadelphia Phillies , who are headed home still with a shot at a third straight National League pennant thanks to Halladay's latest gutsy effort.
"The guy's just a tough guy," Placido Polanco said. "He didn't show it."
Halladay outdueled Tim Lincecum and kept the Phillies alive with a 4-2 victory over the San Francisco Giants on Thursday night that pulled Philadelphia to 3-2 in the NL championship series.
Now, the Phillies will turn to their other star Roy - Oswalt - to keep them going in Game 6 on Saturday back home at Citizens Bank Park. Oswalt beat the Giants in Game 2, then was the loser in relief in Wednesday night's Game 4. He is 10-0 in 12 starts in Philly this year.
Jonathan Sanchez goes for the Giants, who need one win in two tries to reach their first World Series in eight years.
"Obviously, we play good at our ballpark in front of our fans, and kind of regained home-field advantage a little bit," right fielder Jayson Werth said.
With the New York Yankees facing the Texas Rangers in Game 6 of the ALCS on Friday night, it is the first time since 2004 that both league championship series have gone at least six games.
Having spoiled the Giants' clinching party, the Phillies headed off on a redeye charter hoping to stage a celebration of their own this weekend.
A few of Halladay's teammates had noticed he wasn't at his best when his velocity dropped.
"It was just something to deal with. You make adjustments and pitch your way through it," Halladay said of his injured right groin. "We know we can win. It's a matter of going out and doing it. We continue to plug away."
Werth's solo homer in the ninth quieted the raucous sellout crowd of 43,713, and many fans began making for the exits even before the final out. Werth's 13 career postseason homers are tied for the most by NL players.
A bunt by Halladay - which appeared to be foul - also helped spark a three-run third inning, when Shane Victorino drove in the first of two runs that scored on a fielding error by first baseman Aubrey Huff .
Victorino's hard grounder hit off the bottom of Huff's glove and wound up in shallow center field as two runs scored. Polanco followed with an RBI single that made it 3-1.
Halladay improved to 2-1 with a 2.45 ERA in three postseason starts this year, doing it despite the injury, which he sustained in the second inning.
"Of course, he stayed in there," Phillies manager Charlie Manuel said. "He was determined he was going to stay in there."
Philadelphia took this matchup of Cy Young Award winners after Lincecum came out on top in the opener. The Giants now must win once in two tries on the road for the franchise's fourth pennant since moving West in 1958. San Francisco has not been to the World Series since the Giants' Barry Bonds -led team lost Game 7 to the Angels in 2002.
After Ryan Madson struck out the Giants' 4-5-6 hitters in the eighth, Brad Lidge finished with a perfect ninth for his second save this postseason.
Philadelphia will try to become the 12th team to rally from a 3-1 deficit in a best-of-seven series. The Red Sox were the last to do it, in the 2007 ALCS against Cleveland.
"From our perspective, we see ourselves more in the driver's seat than them," Lincecum said.
San Francisco put the possible tying run in scoring position in the fourth, fifth and sixth innings but couldn't capitalize, losing in a potential postseason clincher at home for the first time since Game 7 of the 1962 World Series against the New York Yankees .
In a series dominated by pitching, the Phillies are hitting just .209 and the Giants .220. Little has separated the teams - and despite trailing in the series, Philadelphia has outscored San Francisco 18-16.
Halladay stared down Pat Burrell after a called third strike to end the first, and Burrell jawed at Halladay while sprinkling in profanities. Clearly fuming in the dugout, Halladay returned to the mound seemingly unfazed by that moment or a steady drizzle that hit during parts of the later innings.
Lincecum, the two-time reigning NL Cy Young Award winner, was 2-0 so far this postseason and pitched another solid game except for one rough inning, but the offense failed to back him.
"We just didn't play great fundamental baseball tonight," Huff said. "No doubt the error was big but we weren't able to get the big hit with runners in scoring position."
Cody Ross , who homered twice off Halladay in Game 1, struck out swinging to start the second but hit an RBI double in his next at-bat in the fourth to pull the Giants to 3-2. Burrell doubled ahead of Ross, but the Giants did little else.
"With this club, we don't do anything easy," manager Bruce Bochy said. "What they've been through, they'll put this behind us. Believe me, under no illusion did we think this was going to be easy playing a great club."