WASHINGTON -- Pinch-hitter Hector Sanchez hit a two-strike, two-out home run in the top of the ninth inning to lead the San Francisco Giants to a stunning 4-3 victory over the Washington Nationals on Thursday.
After Buster Posey singled to lead off the ninth against Washington closer Rafael Soriano (2-3), Roger Kieschnick drew a two-out walk. Sanchez worked the count full against Soriano and then hammered a pitch into the second deck just inside the right field foul pole for his first homer of the season.
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 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.
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) picked up the victory.
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.
The Nationals loaded the bases against Giants starter Ryan 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 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.
NOTES: The Nationals made a reliever swap Thursday, 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.