WASHINGTON -- Hector Sanchez has spent a frustrating season bouncing up and down between the San Francisco Giants and Triple-A while also dealing with a shoulder injury he suffered playing winter ball.
So the young catcher would not seem like the ideal candidate to deliver a dramatic hit in the clutch. But the Giants know better.
"This kid is good," San Francisco manager Bruce Bochy said.
Sanchez erased his and the Giants' woes with one swing of the bat Thursday, launching a two-out, two-strike, pinch-home run to lead San Francisco to a stunning 4-3 victory over the Washington Nationals.
"You're looking for a good pitch to hit well, and I finally found it," Sanchez said in a jubilant Giants clubhouse.
With the Giants down 3-1 entering the ninth, Buster Posey opened with a single against Washington closer Rafael Soriano. After the Nationals recorded two outs, Soriano walked Roger Kieschnick, setting the stage for the unheralded Sanchez.
After falling behind 0-2, Sanchez took three tough pitches, including a 2-2 fastball that just missed the plate.
"I thought that was the game, right there," Soriano said. "I thought it was a strike. But that's not my decision."
Sanchez then hammered a 3-2 fastball into the second deck just inside the right field foul pole for his first homer of the season as the Giants avoided a three-game series sweep.
"It was tough," said Sanchez, in the middle of his third stint was the Giants this year. "You have to be focused in that at-bat. I took a couple of pitches close to the strike zone and that was a big part."
Sergio Romo pitched the bottom of the ninth for his 29th save, getting some defensive help from shortstop Brandon Crawford, who robbed Bryce Harper of what would have been a leadoff single.
"The boys needed this," Bochy said. "They needed it bad. Good for them. It saved a little sanity around here."
The comeback halted Washington's five-game winning streak and spoiled a fine effort from Nationals starter Dan Haren, who pitched six innings of three-hit ball. Ian Desmond had a two-run double in the loss.
"It's tough, but we had a lot of runners on base and we didn't push them across," Desmond said. "We have to do a better job of pushing runs across. Different guys had opportunities, including myself."
San Francisco avoided a series sweep and won for the first time in its last eight games at Nationals Park. The Giants improved to 5-54 when trailing after eight innings.
Javier Lopez (2-2) claimed the victory as five San Francisco relievers picked up the slack for ineffective Ryan Vogelsong, who lasted just 3 2/3 innings.
"Bullpen - they just did a great job," Bochy said. "Lopez, we were running short on pitching and he had to face some righties. And he did a great job. It didn't look good. Every inning, they had men on base, it seemed like, but we fought hard."
Both starters had early issues but only Haren was able to wiggle his way out of trouble, getting Pablo Sandoval to pop up with the bases loaded in the top of the first to end the Giants' best threat before the ninth.
The Nationals loaded the bases against Vogelsong in the second, but he struck out Haren to escape the jam.
Vogelsong would not be so lucky in the third in another tough situation. With runners on second and third and two outs, Desmond drilled a breaking pitch to the base of the left field wall for a two-run double and Adam LaRoche followed with an RBI single to give the Nationals a 3-0 lead.
Brandon Belt hit his 15th homer in the season in the sixth inning, his second in as many games.
NOTES: The Nationals made a reliever swap, recalling RHP Drew Storen from Triple-A Syracuse and optioning RHP Ryan Mattheus to the minors. Storen was 3-2 with a 5.95 ERA in 47 relief appearances in Washington, but while in Syracuse he tinkered with his delivery during six strong appearances. Mattheus is 0-1 with a 6.26 ERA in 23 games for the Nationals this season and had a rough outing on Wednesday, allowing two runs without retiring a batter. ... San Francisco OF Angel Pagan will play three innings during a rehab assignment with the Giants' rookie league team in Arizona on Friday. Pagan, on the DL with a strained left hamstring, has missed 68 games. ... Both managers had interesting thoughts on the proposed replay challenge system that could take place next season. "I've got to get my arm back in shape," Giants manager Bruce Bochy joked, referring to NFL coaches throwing review flags. "I'd be challenging 20 times per game," said Nationals manager Davey Johnson, who plans to retire at the end of the season. ... The Giants' road trip continues Friday with a three-game series in Miami. Washington looks to improve its 3-10 mark against the Braves with a three-game series in Atlanta.