SAN FRANCISCO (Ticker) -- Tony La Russa picked his poison and the result likely killed any chance his St. Louis Cardinals had of winning the National League Championship Series.

After an intentional walk to Barry Bonds with two outs and none on in the eighth inning, Benito Santiago rose to the challenge and hit a two-run homer that lifted the San Francisco Giants to a 4-3 triumph over the Cardinals in Game Four of the NLCS.

The win gave the Giants a three games to one edge and moved them within one victory of their first World Series appearance in 13 years.

La Russa said before and during the series that he would pitch to Bonds appropriately and within the context of the game. After Rick White (0-1) got the first two batters in the bottom of the eighth, La Russa bypassed going to lefthander Steve Kline and opted to have White walk Bonds, who set a major league record with 68 intentional walks during the season.

That brought up Santiago, who continued his remarkable All-Star season by launching a 3-2 pitch midway up the left field bleachers for his second homer of the postseason.

"It was a dream come true," Santiago said. "When I hit that ball, I knew I hit it hard, and what I remember is the time before that, they struck me out with the same pitch. And this time it was 3-2 and I was looking and tried to put the good side of the bat on the ball, and it happened."

"It was a strike on the inside, but I left it out over the plate too much," White said. "When Benito swung, he spun, so I thought the worst he would do was pop it up. I couldn't believe it. I don't give up many home runs, especially in that situation."

La Russa addressed the thought process behind the decision.

"A lot of times strategy is judged on whether it works," La Russa said. "So it didn't work, bad strategy, but Bonds is the most dangerous hitter in the game right now, and it's tough to walk in that clubhouse after giving him a chance to get the hit to beat you. Santiago has been very tough, but it's a little easier to take.

"We treat Bonds like the really dangerous hitters in the league. ... In all cases, we respect him and we are going to pitch to him like he's a dangerous hitter. The game dictates what you are allowed and not allowed to do."

White agreed with his manager's strategy, saying, "You don't want to give Bonds a chance to beat you. That's our game plan. I thought I could get Santiago out, I didn't. That's baseball."

The 42,676 fans at Pacific Bell Park still had to endure a gut-wrenching ninth as Kerry Robinson and Fernando Vina reached to open the inning. After a groundout by Edgar Renteria moved both runners into scoring position, Jim Edmonds came up with an RBI single that got St. Louis within 4-3.

With runners at the corners and one out, Nen struck out slugger Albert Pujols and J.D. Drew to earn his fifth postseason save.

"I knew I had to get strikeouts for those last two outs," Nen said. "The tying run is on third ,so I have to get my pitches in there. I knew if I made my pitches I'd could get it done."

Tim Worrell (1-0) got the final two outs in the eighth for the win.

San Francisco can close out the series Monday, when it sends Kirk Rueter to the mound against Cardinals ace Matt Morris.

"The easiest way to get fired up for a game is to have your back against the wall," Cardinals first baseman Tino Martinez said. "We have our backs against the wall. We get a win tomorrow, we go home with the home-field advantage."

"You can't get down now, you have to play like there is no tomorrow because, well, there is no tomorrow," Pujols added.

St. Louis starter Andy Benes allowed two runs and just two hits in 5 1/3 innings. He walked four but struck out five.

The Cardinals got to San Francisco starter Livan Hernandez for a pair of runs in the opening inning. Vina started the game with a double, took third on a flyout and scored on a groundout.

Hernandez drilled Pujols in the back with a pitch and Drew and Martinez followed with singles for a 2-0 cushion. With a chance for the Cardinals to break open the game, Hernandez got Eli Marrero on a bouncer to third.

Santiago flied out with two aboard to end the bottom of the first.

The Cardinals left a runner at third base in the second inning and the bases loaded in third. Benes did not help himself in the sixth, grounding out with two aboard to end the inning.

Benes got himself in trouble in the bottom of the inning, issuing consecutive one-out walks to Jeff Kent and Bonds. La Russa opted for White, who struck out Santiago on four pitches.

With lefthanded-hitting J.T. Snow at the plate, La Russa could have gone to Jeff Fassero, who was warming up. Instead, he stuck with White and Snow drilled a long two-run double that tied it. White limited the damage by striking out slumping Reggie Sanders.

"He gave me a pretty good pitch to hit and I hit it about as well as I can hit it, I guess," Snow said.

"White was nice and fresh," La Russa said. "We were trying to get a nasty pitch. He just got a sinker up a little bit, and give Snow credit."

Santiago's home run came on White's 41st pitch and was the 14th homer of the series, establishing a new NLCS record.

"On that last at-bat, I threw inside to move him off the plate and, I thought he'd be looking away again," White said. "He just hit it. He didn't fall for it. He was looking for something to drive and lofted it out of here."

"We don't want Bonds to beat us in that situation," Benes said. "You try not to let Bonds hit one in the water. ... That's our game plan going in. You don't want Bonds to be a wrecking crew. You make sure someone else beats us. Tonight, J.T. Snow and Benito Santiago beat us."

Pujols left a runner at third in the seventh and Mike Matheny stranded Martinez at third in the eighth as the Cardinals were 2-for-17 with runners in scoring position.

Hernandez allowed just two runs despite scattering nine hits and a walk. He struck out none and was unable to improve his 6-0 career postseason mark.

"This is great," Hernandez said. "If we win tomorrow, we got it. It would then be a California Series, us and Anaheim. Beautiful California."

"I think we wanted this really badly," Giants shortstop Rich Aurilia said. "We knew it could be big if we could win here and go up 3-1. We wanted the win so we could close out the series here."