SAN FRANCISCO -- The Phillies rallied to give Roy Oswalt another chance in the National League Championship Series.

Oswalt's surprise relief appearance in Wednesday's Game 4 ended in a loss that left the Phillies' backs against the proverbial wall, but they beat the Giants, 4-2, in Game 5 on Thursday to send the series back to Philadelphia. Game 6 is Saturday at Citizens Bank Park, and Oswalt will be back on the mound.

"I'll be ready," Oswalt promised.

Tale of the Tape: NLCS Game 6
2010 Regular Season
Overall: 32 GS, 13-13, 2.76 ERA, 55 BB, 193 Ks
Overall: 33 GS, 13-9, 3.07 ERA, 96 BB, 205 Ks
Key stat: League-leading 1.025 WHIP
Key stat: 8-4, 2.27 ERA in past 12 starts
Postseason
2010: 3 G, 2 GS, 1-1, 3.29 ERA
Career: 11 G, 9 GS, 5-1, 3.58 ERA
2010: 2 GS, 0-1, 2.03 ERA
Career: 2 GS, 0-1, 2.03 ERA
At CITIZENS BANK PARK
2010: 7 GS, 6-0, 1.81 ERA Career: 11 GS, 10-0, 2.10 ERA
2010: 2 GS, 1-1, 1.93 ERA Career: 3 GS, 1-2, 1.80 ERA
Against this opponent
2010: 6 G, 5 GS, 2-4, 2.78 ERA Career: 19 G, 18 GS, 7-9, 3.57 ERA
2010: 3 GS, 2-1, 1.89 ERA Career: 10 G, 6 GS, 3-2, 2.88 ERA
Loves to face: Pat Burrell (4-for-18)
Hates to face: Freddy Sanchez (11-for-36)
Loves to face: Jimmy Rollins (1-for-16)
Hates to face: Shane Victorino (6-for-15)
Game breakdown
Why he'll win: Unbeaten in Philly and October veteran
Why he'll win: Won NL West-clinching regular-season finale
Pitcher beware: Threw 18 pitches in Game 4 relief appearance
Pitcher beware: Checkered history in prime-time situations
Bottom line: This is why he's here
Bottom line: He's clinched before
He made that pledge after volunteering to work the bottom of the ninth inning of Game 4, when the Phils were nearing the end of their bullpen choices. Oswalt's second career postseason relief appearance was a forgettable one, marred by two Giants singles and a game-winning Juan Uribe sacrifice fly that left Philadelphia one loss from elimination.

Oswalt walked off the mound with his head down and had to dodge the Giants' raucous celebration. But his own teammates applauded the extra effort.

Now Oswalt is getting another chance. If the Phillies can win Saturday, they'll have 2008 postseason hero Cole Hamels ready for Game 7.

"I think everybody has got to feel good about our situation," Roy Halladay said after his win in Game 5. "We're going back to our place with two of our best pitchers down the stretch going back out there. We needed to get back to Philly, and we're looking forward to it."

And outfielder Shane Victorino: "We'll take our chances with Roy and Cole. We like where we're at right now."

The Phillies and Giants split the first two games of the series at Citizens Bank Park. Cody Ross hit two home runs in the Giants' Game 1 win before Oswalt pitched, hit and ran his way to a win in Game 2. The power-hitting Phils were 54-30 at home during the regular season.

"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. "This is really good for us to get back there. Obviously we needed to win one game to get home, we did that, and we'll head back to Philly. ... We're a focused bunch, and we've got some professional guys in there and some really good players. We still know what we're doing."

Oswalt would like a chance for redemption. His loss in Game 4 was Oswalt's first in 11 career postseason appearances. He fell to 5-1 with a 3.58 ERA in nine playoff starts and two relief appearances and 3-1 with a 2.91 ERA in the NLCS.

In Game 6, Oswalt will return to his usual starter's routine, looking for the kind of success he enjoyed in Game 2. The right-hander worked eight stellar innings, didn't allow a hit until the fifth and gave up only three hits and one run overall to erase the memory of a subpar outing in Game 2 of the NL Division Series against the Reds on Oct. 8.

Oswalt made up for the run he allowed by scoring one himself. He blew through third-base coach Sam Perlozzo's stop sign to score a run that sparked a four-run Phillies seventh inning in a 6-1 win.

"You've got a little more adrenaline going when you go out there [in the postseason]," Oswalt said that night. "But you still have to treat it as a game, and that's what it is. You can't get caught up in the moment of trying to get the momentum back on your side. You have to pitch your game. From the very beginning, I told myself, 'All you can give is 100 percent. If it ain't good enough that night, go try to get it next time.'"

If Oswalt and the Phillies don't win again in Game 6, next time won't come until 2011.