Pablo Sandoval felt like hell, and not because his teammates gave him the same kidney shots he administers when one of them ends a game with a hit. Sandoval was so sick, he took intravenous fluids before Tuesday night's big matchup between Matt Cain and Stephen Strasburg.

It's funny how much better a player feels after he hits a ball from here to dang near eternity to win a ballgame. Sandoval was glowing, maybe from joy, maybe from fever, and smiling after his two-run homer in the 10th inning gave the Giants a 4-2 win and a series victory over the Nationals.

"I don't know, man," Sandoval said, when asked how he could be that sick yet play 10 innings and hit what might have been his longest homer at AT&T Park, to Barry Bonds country in right-center field.

"It's effort," he said. "You have to give 100 percent no matter what because it's your job to fight."

The fight would have been lost had Gregor Blanco not hit an RBI triple off closer Rafael Soriano when the Giants were trailing 2-1 in the ninth and down to their last strike.

Or, had Cain not steadied himself after allowing two first-inning runs and kept the Giants in the game against Strasburg, who was tough.

Each starter struck out seven in seven innings, but Strasburg allowed only one run. Blanco scored it after one of his two singles against Strasburg. Cain moved Blanco over with a nice bunt on a fastball riding toward his hands, and Angel Pagan singled him home.

This was one of those landmark wins that the Giants will remember weeks and months hence, not just from the excitement of Sandoval's second career walk-off homer - the other was against the Nationals, too - but also in light of recent events.

One night earlier, they lost starter Ryan Vogelsong for up to two months with a broken right hand, adding injury to the insult of an error-ridden 1-5 trip. Not coincidental to Tuesday night's win, the Giants played their first errorless game since the last homestand.

"That's the thing about baseball," Cain said. "There are so many games and so many injuries that come about. But there's a game the next day, and you can't sit around and think about it. It was hard to see Vogey go down. We're glad things look like they should be OK. You have to move on really fast, and the guys did that."